It was about fifteen years ago that the term “organic” became mainstream. In 2002 when the USDA released the national standards for organic products, consumers joined the movement, and organic food sales grew by 20% in one year. Another year later, organic items were available in 73% of conventional grocery stores.
It’s no surprise that people are attracted to organic products. In general, the public perception of pesticide and fertilizer-free food being safer and healthier, contributes to a higher demand for these natural products. However, there is not enough medical literature to prove whether or not organic foods are actually “better” for you.
The same can be said for organic or natural personal hygiene products, such as sulfate-free shampoos, which also rose in popularity within the past decade. With claims of healthier hair and less fading in color-treated hair, sulfate-free shampoos would seem to be the right option for hair care. But, the promises do not take this into consideration: Just like no two snowflakes are the same, neither are women’s hair types and styles. With such hair diversity, it’s tough to prove that one type of shampoo is universally the best.
The Science of Sulfates
When talking about chemicals in shampoos, Sodium Lauryl Sulfate (SLS) or Ammonium Lauryl Sulfate are the main types of sulfate. SLS is an active ingredient in shampoos responsible for the suds and lather of a traditional shampooing. As a whole, Lauryl Sulfates improve the foam and surface activity of the product’s ingredients to cover more of your scalp and hair. Shampoos with sulfates will foam as you massage your hair through your fingers.
According to the Cosmetics Database, sulfates have a low overall hazards rating, meaning its ecotoxicology is of low concern for users. Additionally, SLS is not known to cause cancer or have reproductive or developmental toxicity, in moderate usage.
Some shampoos combine sulfates with other surfactants. Essential Chemistry breaks down surfactant science like this: “Surfactants function by breaking down the interface between water and oils and/or dirt. They also hold these oils and dirt in suspension, and so allow their removal.” When sulfates are combined with surfactants, both foaming and cleansing principles are present in the shampoo.
But how exactly do surfactants break down the interface? It’s because they contain “both hydrophilic (water loving) group, such as acid anion, and a hydrophobic (water hating) group, such as an alkyl chain.”
Another study delves into the benefits of combining sulfates and surfactants for optimal results. This study, published in the International Journal of Cosmetic Science, fleshed out the properties of a soybean oil-based polymeric surfactant (SBPS) for personal-care products and evaluated its performance. The results prove that in “examination of SBPS/SLS mixtures in model shampoos showed that the presence of the SBPS enables the concentration of SLS to be significantly reduced without sacrificing shampoo performance.” Surfactants strengthen the mixture and contribute to improved cleaning, foaming and conditioning. But what if you have color-treated hair?
Sulfates Don’t Necessarily Decrease Color in Treated Hair
We know that combining sulfates and surfactants can have a positive effect on the hair washing experience. But also, when sulfates and surfactants work together, the combination can combat fading in color-treated hair.
Hair color can and will fade in time. But the main cause of decreasing color? Water.
Perry Romanowski, a cosmetic chemist who once worked with the maker of Tresemme, explains it this way: “Any time you expose hair color to water, hair swells up and some color can leak out. But the shampoo you use is not really going to pull color out appreciable more than anything else.”
But what if sulfate and surfactant shampoos were better for color-treated hair? The University of the Arts London completed a study on the addition of a co-surfactant in shampoo to decrease color fading. You’ll still get the lather and cleaning experience, but you’ll have a decreased risk of color fading.
This additional conditioning element created a synergistic fortification for color retention.
The Rise of Sulfate-Free Shampoo
So if science has shown combining sulfates and surfactants may actually be good for your hair, why is the market still inundated with sulfate-free shampoos?
When hair products are sulfate-free, they will not have SLS as an ingredient. Many studies blame sulfates for frizz, lackluster locks, and split ends. But there’s not enough science to back up claims, like there is with hard and soft water being the reason for dry hair.
Dr. Rebecca Baxt, a New York-based dermatologist, explained the abundance of sulfate-free products asserting, “I think there are so many chemicals in our personal hygiene products, foods and environment that people have become more aware and rightly concerned about the effects of all of these chemicals. Anything with fewer chemicals has become more popular.
No Harm, No Foul
At this point in time, it seems unnecessary to blame sulfates for everything you don’t like about your hair. If you’ve found a shampoo and conditioner routine that works for your hair – be it sulfate-free or packed with SLS – then it’s okay to stick with what you know.
The Cosmetic Ingredient Review states that there is “no evidence of harm from the use of SLS in cosmetic products, where there is intentional, direct contact with the skin.” However, it’s important to recognize skin irritation.
All hair is diverse. That’s why it’s so important to specialize your hair care regimen. At Shtrands, we’re taking our passion for beauty, science and emotion in their crudest form we guide our guests in creating a foundation on which they are able to create their version of individuality into the physical realm.
Shtrands offers a subscription-based hair care regimens that are personalized for each guest’s hair type and personal needs. Every 2 or 3 months (your choice) you will receive 4 full-size, luxurious products that are tailored for you, partnered with hair care directions to ensure maximum benefits. All the products are curated and matched to your unique hair/scalp parameters by our hair care professionals and cosmetic chemists.
There is no worse feeling than getting a product you have seen in every magazine and all your friends have tried and loved, then when you use it you end up with a terrible reaction.
The skin is our largest organ and I has been reported that it can come into contact with over 100 different chemicals daily just from the products we use. So it is not surprise that many women are opting for a more ‘natural’ alternative, but can we really trust these companies to keep us completely safe.
Firstly it is important to mention that there is no agreed meaning for the word natural in cosmetics, just because a label says natural it does not mean it has had any more rigours testing or even proof that less harmful chemicals or process are used.
Some women will experience sensitivity to products and this can range from a mild reaction of redness or pain to life threatening injures or even death due to an allergic reaction, therefore it is important to know could be risky and which ingredients to avoid.
There are strict regulations and formulations are tested to make sure they do not cause harm to the general public however this does not mean that no one will have an adverse reaction.
An allergen is described as a particle, which the body responds to inappropriately after repeated exposure. This means you will not have a reaction the first time you are exposed but the body will treat it like an enemy the next time it comes into contact with it. This is different to an irritation with usually less severe and localized reactions.
When purchasing new products, and if you know you have sensitive skin, the most important place to look is the ingredients list. This will give you the bulk of the information you need to decide if the product will be good for you. Do not be put off by long or complicated Latin chemical names. If you know what you are allergic to (soy for example), make sure you know the chemical composition of that and their Latin names and look for those in the ingredients list. Many times you will not find soy, but one of the chemicals in soy that might give you allergic reactions.
Most allergens and irritants are found in the preservatives and fragrances used to give the products a long shelf life and nice smell. Hair dyes are also a big culprit. Some companies will not list their exact ingredients and in my opinion there should be no secrets when it comes to your skin or scalp. A lot of these fragrances may come from plant extract which is why they are considered natural but can still cause a reaction regardless of where they are derived.
Some common irritant to look out for are Treenuts, Gluten, Oats, Soy and Wheat, some preservatives, Fragrances (many of them extracted from natural sources), Sodium layrl sulphate, Alcohol and Paraphenylenediamine (PPD).
They may be listed with their common name or disguised using the full Latin name. It is important to take ownership and research the products you use.
Carrageenan for instance are a family of linear sulphated polysaccharides that are extracted from red edible seaweeds. They are widely used in the food industry, for their gelling, thickening, and stabilizing properties, but they are also used in hair products and personal lubricants as thickeners. If you are sensitive to saccharides, be careful when you buy products labeled as natural because many plants contain them.
Also some companies will claim to be free from these main offenders but use a compound that is very similar. If you get a sample of a product, always complete a patch test before trying a new product and list the ingredients of those that have caused you problems so you can avoid them in the future.
At Shtrands, each of our customers has a unique profile where she can list any chemicals or ingredients they are aware of to be sensitive to. We are making sure that these ingredients are not present in their products and help them figure out the chemical names of them.
If scientists ever find a cure for menopause, our big problem will suddenly become global cooling.
Many women experience a variety of symptoms as a result of the hormonal changes associated with the transition to menopause. It’s that time when your days start backwards, waking up tired and going to bed fully awake.
We read articles about how menopause can be a time of reflection and insight, prompting you to embrace the new stage in your life; how it is a bit like being a teenager again, only with a full tank of gas and one’s own car keys.
The reality is that as we age, we experience changes in our skin and hair, and our waists change from an hourglass shaped to an apple shaped one 🙁
Menopause is nobody’s friend, except maybe the moisturizing and cosmetic surgery industry.
Now that I put you in a good mood :-), lets see how menopause affects the hair.
Menopause can affect hair
On average, the age of onset of the menopause is 50 years, but it may vary among women, ranging from 45 up to 56 years of age (1). This period manifests as a reduction in estrogen hormones and increase in the androgen concentration. These hormonal changes affect some hair characteristics and are responsible for hair thinning. Almost 20-60% of women before reaching the age of 60 suffer from hair thinning. (4).
The hair strand diameter also can decrease, especially in the frontal and parietal areas. Studies showsa decrease in copper and calcium concentrations in hair. Age related decrease in hair copper and calcium concentration is observed in perimenopausal women (5,6), which makes the hair brittle.
As the hair thinning wouldn’t have been enough, facial hair tends to increase after menopause even in the elderly (9). Cute moustache anyone? The prevalence of facial hair growth has not been fully documented, but it is supposed that about 50-70% of women report excessive facial hair growth after menopause, even though there is no hormonal replacement therapy (9).
Now, it is well worth it to note that a lot of drugs used to treat different types of conditions can affect hair. Some drugs can lead to increased hair loss while others, can stimulate hair growth or even change their shape or color. Usually these are temporary and elimination of the drug and good nutrition will facilitate hair regrowth. For example, anticoagulants cause hair thinning in 50% of the patients, which occurs 1-12 weeks after the last dose is administered. Drugs used in neurology are also responsible for drug induced alopecia, like Carbamazepine or Valproic acid (7).
What shall we do? Good nutrition is critical.
During this period of time, apart from the hair products that give us a cosmetic fix and some topical treatments, it’s actually very important to eat a balanced diet that can prevent the deficiencies of vitamins, proteins and minerals taking parts in hair building process.
I am not a fan of supplements, and believe that many people take them unnecessarily and actually sometimes you get the opposite effects. For example, if you take to much Zinc, this can lead to copper and calcium deficiency, drowsiness and headaches, and makes hair brittle. Also zinc decreases the iron uptake, so if you have same amount of zinc and iron on your bottle, you’ll basically absorb no iron (10).
Good sources for a balanced diet for women that influence hair health
Proteins: cottage cheese, yoghurt, fish, meat (veal, beef), poultry (turkey, chicken), legume seeds (soya, lentils, beans, peas, broad beans), seeds (pumpkin and unflower seeds, sesame), nuts (pistachio, peanuts), grain products (buckwheat, barley groats, hulled barley, brown rice, rye whole-meal bread and graham bread), eggs.
Fats: fish, flax seeds, walnuts, wheat sprouts, poultry, eggs, olive oil and rapeseed oil.
Carbohydrates: full grain breads, grits, rice, whole meal pasta, vegetables and fruit with low glycemic load.
Vitamin C: vegetables (green parsley leaves, kale, horseradish, peppers, Brussels sprouts, broccoli, cauliflower, spinach and savoy) and fruit (black currants, strawberries, wild strawberries, kiwi, red currants and citrus fruit).
Vitamin D: fat fish (marcel, salmon, sardines), whale or tuna liver oil, and also products containing lower amounts such as meat, poultry, eggs and full fat diary, mushrooms.
Folates: kale, brussels sprouts, green peas, dry peas, white beans, asparagus, beets, kohlrabi halibut, cod but also in small amounts consumed eggs and poultry liver.
Vitamin B5: mushrooms, cauliflower, liver, soya, hen eggs, and baking yeast, whole grains, beans, milk and green leafy vegetables.
Biotin: meat, liver, egg yolk, yeast and some nuts.
Niacin: meat, whole wheat grains, legume vegetables, seeds, milk, green leafy vegetables, fish, peanuts, shellfish and yeast.
Vitamin B12: meat, fish, eggs, milk and dairy products and seafood.
Minerals that influence hair growth are: Zinc, Iron, Copper, Selenium, Silicon, Magnesium and Calcium: beef and pork, poultry, pork and lamb liver, fish) milk/dairy, soya, white beans, pistachio nuts, green parsley leaves, dried apricots, figs, garlic, chives (for silicon), cacao (for magnesium).
Antioxidants (flavonoids): despite the fact that the highest number of flavonoids can be found in bitter chocolate (> 70% of cocoa), the main source of flavonoids in women diet should be vegetables (onions, tomatoes, peppers, broccoli) and fruit (apples, berries, black currant, citrus fruits and grapes). Flavonoids also can be found in some grains, seeds of lentils, spices and red wine (yes!), green tea, coffee, tea and cocoa.
à votre santé, Ladies!
- Słopień R, Warenik-Szymankiewicz A: Przekwitanie. [W:] Bręborowicz GH (red.): Położnictwo i ginekologia. Wyd. I, Wydawnictwo Lekarskie PZWL, Warszawa 2010: 716-725.
- Herskovitz I, Tosti A. Female pattern hair loss. Int J Endocrinol Metab. 2013;11:e9860.
- Imko-Walczuk B, Cegielska A, Głombiowska M. Changes in hair distribution in postmenopausal women. Przegl Derm. 2012;99:62–67.
- Shapiro J. Clinical practice: Hair loss in women. N Engl J Med. 2007;357:1620–1630
- Wlaźlak E, Dunicz-Sokolowska A, Radomska K et al.: Analysis of hair copper concentration in perimenopausal women. Prz Menopauz 2007; 6: 303-305.
- Wlaźlak E, Surkont G, Dunicz-Sokołowska A et al.: Analysis of calcium concentration in perimenopausal women hair. Prz Menopauz 2007; 6: 51-54.
- Burrows NP, Grant JW, Crisp AJ, Roberts SO: Scarring alopecia following gold therapy. Acta Derm Venereol 1994; 74: 486.
- Bartosz Miziołek1 , Ligia Brzezińska-Wcisło2 , Dominika Wcisło-Dziadecka3 , Martyna Zbiciak-Nylec1 , Anna Michalska-Bańkowska, Thricological Problems related to menopause, Postępy Nauk Medycznych, t. XXVIII, nr 3, 2015
- Piérard-Franchimont C, Piérard GE: Alterations in Hair Follicle Dynamics in Women. BioMed Research International, vol. 2013, Article ID 957432, 5 pages, 2013. doi:10.1155/2013/957432.
- Zuzanna Sabina Goluch-Koniuszy, Nutrition of women with hair loss problem during the period of menopause, Menopause Rev 2016; 15(1): 56-61
*Image from Journal of the European Academy of Dermatology and Venereology,26(8):953-63 · July 2011.
Cupuacu is an Amazonian forest tree, having probably a pre-Colombian origin. Each tree produces about 20-30 fruits, having 15-25 cm in lengths and 10-12 cm in diameter, and 800g – 2kg in weight (that’s a very heavy fruit!). The fruit contains 30-50 seeds surrounded by a creamy yellowish pulp (almost 50% of the fruit), possessing a strong and pleasant scent (1). This pulp provides the Cupuacu butter and the seeds have a high fat content (62%) with characteristics that resemble that of cocoa butter (2).
Cupuaçu butter is used by the cosmetic industry in both hair and skin care formulations.
The unique aroma
Fruits of Cupuacu are very much appreciated for its acidic and highly flavored pulp and they are used in juices, ice creams and gems.
Forty-five volatile compounds were identified and 14 tentatively identified in cupuaçu pulp. Among them, 35 compounds were reported for the first time in this fruit. The olfactive characteristics of several compounds showed that linalol, α-terpineol, 2-phenylethanol, myrcene, and limonene were contributors of the cupuaçu pleasant, floral flavor, and ethyl 2-methylbutanoate, ethyl hexanoate and butyl butanoate contribute to the fruity aroma. Diols like (2,6-dimethyl-oct-7-en-2,6-diol are possible contributors of the typical exotic scent. Moreover, hexadecanoic acid can be considered as a contributor of the grassy, heavy odor of cupuaçu (3).
The reason I listed all these chemical compounds present in Cupuacu fruit here is to show my aversion towards the adage floating around “If you cant pronounce it, don’t eat it” which bothers me on many levels, from the terrible impracticability to downright ignorance. Imagine someone would list instead of cupuacu all these chemical names on a label. The followers of this adage would definitely find the product “bad”, “not good for you”. I personally have hard time pronouncing “Cupuacu”. Actually, I have no clue how to pronounce it.
Cupuacu butter in skin care
Cupuacu butter is an excellent emollient that restores elasticity to the skin while providing anti-oxidants and hydration (4).
It is very good for dry, sunburned and aging skin.
Cupuacu butter is comprised of long-chain fatty acids that are a perfect mixture of saturated fatty acids (57%) and unsaturated ones (~43%) that makes the butter to be absorbed quickly into the skin (5).
Cupuacu’s ability to penetrate the skin quickly and to retain moisture is unparalleled and far superior to that of shea butter or lanolin (6). Cupuacu butter could support 440% of its weight in water, which means that 1 pound of Cupuacu butter could absorb 4.4 pounds of water! In comparison, shea butter supports 289% of its weight in water (6).
Cupuaçu butter in hair care
The main claims of hair products using Cupuacu butter are improved hydration, softness (emollient), shine, and decreased hair damage after coloring. It not only can act as a sealant but because of its ability to absorb water, it does restore moisture to the hair strands.
It is in particular very performing on thick, dry hair, no matter if the hair is straight, wavy or curly. For women with natural hair who are looking for an alternative to shea butter, cupuacu butter is the one to try.
There is a good research on the effect of Cupuacu butter used in hair formulations applied on dyed hair.
In the lab, hair damage after a dye treatment is measured as protein loss from hair strands. A research study (7) showed that applying hair care formulations containing 1% Cupuacu butter post dye treatment, reduced protein loss with 35%, such that decreased the damage caused to the hair by the coloring process.
It is very important after hair dying to use high quality conditioners to minimize the damage, and to keep using them.
We are happy to provide our members with a shampoo/conditioner combo from Teadora that contains this really performing ingredient. The Teadora conditioner contains also argan oil, which was also scientifically proven to decrease the damage associated with hair dying.
- Boulanger and J. Crouzet, Free and bound flavour components of Amazonian fruits: cupuacu volatile compounds, Flavour and Fragrance Journal, 2000, 15, pag 251-257.
- Alvaro B.A. de Azevedo, Uiram Kopcak, Rahoma S. Mohamed, Extraction of fat from fermented Cupuaçu seeds with supercritical solvents, The Journal of Supercritical fluids, Volume 27, Issue 2, October 2003, Pages 223–237
- Boulanger, R. and Crouzet, J. (2000), Free and bound flavour components of Amazonian fruits: 2. Cupuaçu volatile compounds. Flavour Fragr. J., 15: 251–257.
- Yang H, Protiva P, Cui B, et al: New bioactive polyphenols from theobroma grandilorum (‘‘Cupuacu’’). J Nat Prod. 2003;6:1501–1504.
- V. Gilabert-Escrivá, L. A. G. Gonçalves, C. R. S. Silva and A. Figueira, “Fatty Acid and Triacylglycerol Composition and Thermal Behaviourof Fats from Seeds of Brazilian Amazonian Species,” Journal of the Science of Food and Agriculture, Vol. 82, No. 13, 2002, pp. 1425- 1431.
- Beraca: Rain Forrest Specialties; Data on File – Brazil. 2013.
- Pamella Mello Faria, Luciana Neves Camargo, Regina Siqueira Haddad Carvalho, Luis Antonio Paludetti, Maria Valéria Robles Velasco, Robson Miranda da Gama, Hair Protective Effect of Argan Oil (Argania spinosa Kernel Oil) and Cupuassu Butter (Theobroma grandiflorum Seed Butter) Post Treatment with Hair Dye, Journal of Cosmetics, Dermatological Sciences and Applications, 2013, 3, 40-44.
The highly competitive cosmetics industry is always looking for the “next best ingredient(s)” that can fight the aging process and this led to a sizable increase in the number of anti-aging products on the market. With this is coming an increased number of active ingredients developed for this category; one of these ingredients is stem cell extract.
This is an ingredient that must be assessed carefully, as marketing claims often push the limits of the available science.
Among the plant stem cell extracts that are well supported by science are lilac, grapes and Swiss apples (1).
What are stem cells?
The concept of stem cells originated at the end of the 19th century as a theoretical postulate to account for the ability of certain tissues (blood, skin, etc.) to renew themselves for the lifetime of organisms even though they are comprised of short-lived cells. Stem cells’ isolation and identification happened many years later though.
Stem cells have received a fair share of attention in the public debate — mostly in connection with their potential for biomedical application and therapies. While the promise of organ regeneration have captured our imagination, it has gone almost unnoticed that plant stem cells represent the ultimate origin of much of the food we eat, the oxygen we breathe, as well the fuels we burn. Thus, plant stem cells may be ranked among the most important cells for human well-being.
A stem cell is a generic cell that can make exact copies of itself (daughters) indefinitely. These daughters can remain stem cells or further undergo differentiation (2). Such that a stem cell has the ability to make specialized cells for various tissues in the body, such as heart muscle, skin tissue, and liver tissue.
Plant Stem Cells
Because of their self-renewal functions, stem cells are the most important cells in the skin, as they are the source for continuous regeneration of the epidermis. Stem cell cosmetics are developed based on stem cell technology, which involves using extracts or culture media of stem cells. However, cosmetics containing human stem cells or their extracts have not been released into the market due to legal, ethical, and safety concerns. Meanwhile, plant stem cells, which circumvent these problems, are highly regarded in the cosmetics industry for improving culture technology.
The EU prohibits the use of cells, tissues, or products of human origin in cosmetics; stem cell therapy for anti-aging has not been approved or been deemed safe or effective in USA by the FDA. Furthermore, its use outside of a clinical research trial (which would be listed at www.clinicaltrials.gov) is prohibited. Whereas the Korea Food and Drug Association has allowed the use of sources originating from stem cell media in cosmetics since 2009 (3).
So, any cosmetics marketed as containing stem cells found on US market (should) contain stem cells extracted from plants.
A major difference between animal and plant stem cells is that plant stem cells provide cells for complete organs (branches, leaves, etc.), compared with the animal stem cells, which regenerate cells restricted to one tissue type.
Plants have nowhere to run when times get tough, so they must rely on an inner body plan to generate developmental responses to environmental changes.
Research by many labs in the last decades has uncovered a set of independent stem cell systems that fulfill the specialized needs of plant development and growth in four dimensions. In some long-lived plants, such as trees, plant stem cells remain active over hundreds or even thousands of years, revealing the exquisite precision in the underlying control of proliferation, self-renewal and differentiation.
Plant stem cells in cosmetics
There is some confusion around the term “stem cell” due to the marketing verbiage used by the cosmetic companies. In topical cosmetics the formulations don’t contain stem cells straight out of the plants. They are actually a range of plant stem cell extracts, which are manufactured using a cell culture technology. This technology consists of many and complicated methods that should ensure growth of plant cells, tissues or organs in the environment with a microbe-free nutrient. The plant cell technology allows synthesis of the biologically active substances that exist in plants, but are not commonly available in natural environment or are difficult to obtain by chemical synthesis.
The extracts obtained through this technology from the plant stem cells are currently used for production of both common or professional care cosmetics (4).
Apple stem cell extracts used in hair care
The beneficial apple properties are known for centuries. Apples are cultivated today only for their taste, but earlier the main criterion of the type selection was the “shelf life” of the fruits.
One of such apple-tree types is Uttwiler Spatlauber which is growing in Switzerland. This is a type cultivated solely due to a possible long-time storage of fruits, which remain fresh even for several months. Some trees come from the plant cutting sets planted during the 18th century!!!
The stem cell extracts are made in 2 main steps: first, the tissue material is obtained from apples (collected from a cut surfaces of the apples). Secondly, the material is going through a complicated biotechnological process to make the stem cell extracts that contains certain active ingredients. These are actually the ingredients used in formulations marketed as containing stem cells (5).
Swiss biotech company Mibelle Biochemistry created the product named PhytoCellTecTM Malus Domestica, that is a liposomal formulation (extract) derived from the stem cells of the Uttwiler Spatlauber apples. The company has published in vitro experiments done with hair follicles that showed the ability of the Uttwiler Spatlauber stem cell extract to delaying of the tissue atrophy process (6); this ingredient delays hair aging.
Formulations for healthy hair
We are working with abril et nature one of the leading European laboratories specialized in the research and development of premium hair care products for beauty salons and stylists, to bring their products to our members. Among other high end lines, they produce a “Stem Cell” line that contains stem cell extracts from the same Swiss apple variety, Uttwiler Spatlauber. In addition to the plant cell extracts, the formulations contain other active ingredients, antioxidant oils (from argan, Damascus rose, green tea, black tea and wheat germ) and co-polymers oil-protein, which restore the cortex protein structure.
- Wild, Jennifer, Plastic Surgical Nursing: July/September 2014 – Volume 34 – Issue 3 – p 148–149.
- Thomas Laux, Cell, Vol. 113, 281–283, May 2, 2003.
- Sung Hyun Choi, Jisoo YunSang Mo Kwon, Tissue Engineering and Regenerative Medicine, August 2015, Volume 12, Supplement 2, pp 78–83.
- Acta Poloniae Pharmaceutica in Drug Research, Vol. 71 No. 5 pp. 701-707, 2014.
- Schmid, F. Zülli, Use of Plant Cell Cultures for a Sustainable Production of Innovative Ingredients, SOFW Journal, 2012.
- Schmid D., Sch¸rch C., Blum P., Belser E., Z¸lli F.: SOFW Journal 5, 30 (2008).
Vinegar, from the French vin aigre, meaning “sour wine,” can be made from almost any fermentable carbohydrate source, including wine, molasses, dates, sorghum, apples, pears, grapes, berries, melons, coconut, honey, beer, maple syrup, potatoes, beets, malt, grains, and whey. Initially, yeasts ferment the natural food sugars to alcohol. Next, acetic acid bacteria (Acetobacter) convert the alcohol to acetic acid (1).
In the United States, vinegar products must contain a minimum of 4% acidity (2). White distilled vinegars are generally 4% to 7% acetic acid, whereas cider and wine vinegars are 5% to 6% acetic acid.
So, if the goal is to use something acidic on your hair, you can use any type of vinegar, because all contain acidic acid; you don’t need to use expensive products or certain type of vinegar.
I searched the scientific publications on the benefits (or lack of) of vinegar/acetic acid on hair, and I came up with no result. No trials or in-vitro experiments have been done on this subject (at least not published).
However, many people swear by the hair benefits they got with a vinegar rinse (in particular apple cider vinegar).
Here are some of the benefits and explanations of using a vinegar rinse on your hair. We all have different hair textures, porosity, and hair/scalp dryness levels, use different products and live in different areas, so we all have different hair concerns and #hairgoals 🙂
- After you dye/bleach your hair, an acidic solution can stop the oxidative process and flatten the cuticles. A permanent dye has a pH of 7-8 and bleach a pH of 8-9, so an acidic solution will bring it down to a lower pH.
Note: The pH of the scalp is 5.5 and the hair shaft pH is 3.7 (3).
This flattening may not only help hair color last longer, but also makes your hair easier to comb and a bit shinier.
- Because of low pH, a vinegar rinse can improve the efficiency of the conditioner (4) with polyquats that are positively charged and will adsorb to the hair strand to create lubricity and reduce friction, so it will enhance smoothness and manageability.
- If you live in an area with hard water (see below a map of US water hardness), vinegar may help with removing the build up in the hair caused by the minerals in water. Calcium and magnesium in the hard water react with soaps and detergents to form an insoluble, sticky residue that can be removed with a more acidic solution.
If you want to give it a try (and if you think you really need it), I would recommend using it after shampooing, followed by conditioning. I would not replace a conditioner with just a vinegar rinse (at least for the simple reason that I don’t want to smell like a salad dressing for the rest of the day).
We all have different hair textures, porosity, and hair/scalp dryness levels, so what works on a person’s hair, it might not work on yours.
And remember, these are only folk remedies, not scientifically proven treatments!
PS. Please don’t hesitate to ask me anything, you send any questions through the blog or contact form.
- Vinegar: Medicinal Uses and Antiglycemic Effect, Carol S. Johnston, Cindy A. Gaas
MedGenMed. 2006; 8(2): 61.
- U S. Food and Drug Administration. Code of Federal Regulations. Available at: http://www.fda.gov/ora/compliance_ref/cpg/cpgfod/cpg525-825.html.
- The Shampoo pH can Affect the Hair: Myth or Reality?, Maria Fernanda Reis Gavazzoni Dias, Andréia Munck de Almeida, Patricia Makino Rezende Cecato, Andre Ricardo Adriano, Janine Pichler, Int J Trichology. 2014 Jul-Sep; 6(3): 95–99.
- http://thebeautybrains.com (love these guys).
Among the most significant trends in cosmetics industry is burgeoning interest in organic and natural products and many cosmetics companies started to capitalize on the trend. One good consequence of this trend is that big corporations with big R&D resources started to research more ingredients and chemicals derived from natural resources. The bad outcome however, is that many companies and individuals are coming up with new formulations that are NOT tested for safety, and label their products whatever they want.
As a brief background, under the Federal Food, Drug, and Cosmetic Act, cosmetic products and ingredients (including preservatives) do not require FDA approval before they go to the market, with the exception of color additives. However, companies and individuals who market cosmetics have the legal responsibility to ensure the safety of their products.
This means companies need to demonstrate that their products are not “…contaminated with microorganisms which may be pathogenic, and the density of non-pathogenic microorganisms is low.”
What does “natural” mean?
FDA has not defined the term “natural” or “organic” and has not established a regulatory definition for this term in cosmetic labeling. That means that each company has its own definition or standard of “natural”. Furthermore, an ingredient’s source (either plants, animals or made in the lab) does not determine its safety (1).
I personally can think of 2 possible way of defining a “natural ingredient”:
1) an ingredient extracted from a natural resource such as plants, animals, minerals through physical means (such as cold pressing)
2) an ingredient extracted from a natural source through chemical processes such as extraction, precipitation, distillation or some biotechnological processes such as fermentation. As per the second definition, the original chemical structure or composition of the ingredient may be altered.
Why preservatives are important in cosmetic formulations?
Preservatives in cosmetics are needed for 2 reasons: to prevent primary microbial contamination during the production and to prevent secondary microbial contamination when the product is in use and microbes can be transferred from the consumer into the product.
Cosmetics products can get contaminated with different types of microorganisms (gram positives bacteria, gram negatives ones, molds, yeasts) that can alter the composition of the product or pose a health risk to the consumer. Pathogenic microorganisms such as Staphylococcus aureus, Candida albicans and Pseudomonas aeruginosa are frequently found in contaminated cosmetics, and they are dangerous!!. They can cause skin and eye infections among other health problems.
Just like we humans need water and food to survive, microorganisms need also water and micronutrients to happily grow. And once they have that comfy environment, they spread out very fast.
That’s why cosmetics products that contain water require protection against the growth of microorganisms: to ensure product and consumer safety.
If the products are based on oils or the product packaging is impermeable to microbes (such as aerosols), they might not need a preservative, but still antimicrobial efficacy need to be tested by manufacturers (2).
How can manufacturers minimize the use of synthetic preservatives?
- One way to reduce the amount of the synthetic preservatives is to formulate at lower pH. One way to achieve this is by adding acidic ingredients from natural sources such as salicylic acid, citric acid, lactic acid.
- Another way is to add so called “chelating agents”: they react with metal ions in the microbial cell wall, which enhances the preservatives’ ability to penetrate and destroy the microorganism. One of the most frequently used chelating agents is ethylene-diaminetetraacetic acid (EDTA).
- Preservative systems consisting of an essential oil and a chemical preservative seem to be a good compromise solution (7).
How about using just “natural” preservatives?
Some natural fragrances used in cosmetics have antimicrobial activity, but they are often used in so small amounts that the effect is very small.
Many oil extracts (such as rosemary, thyme, tea tree and lavender, neem, grape seed oils) have some preservative effects and are called natural preservatives, but again, it is necessary to use high concentrations to obtain some efficient preservation.
Another problem with essential oils as preservatives is their relatively low antimicrobial activity in comparison with the commonly used chemical preservatives (6). A further limitation is the acceptance of the organoleptic qualities of the cosmetic with more than 2% of essential oil.
The biggest problem with these oil extracts is that usually they are microorganism specific, which means they are effective against only certain bugs not to a broad range of them. For example a study on using eucalyptus and salvia oils showed that while the oils have some antimicrobial effect on Staph, they don’t have any effect on Candida albicans (3).
Furthermore, both oils and fragrances are composed of many different chemical components and some are highly allergenic (4). Approximately 6% of the general population has a cosmetic-related contact allergy, mainly caused by preservatives or fragrances (5).
Other materials that can be used as natural preservatives are: salt, sugar, bee propolis, cranberry extract. But again, a caveat here, the natural preservative alternatives might not work as well as the synthetic ones, may change structure or may have some unknown health risk.
Any producer’s main concern in formulating a cosmetic product should be in making sure the product is safe for the consumer, not driven by marketing claims.
My recommendation is to pay attention to the water-based “natural” cosmetic formulations, especially if they promote natural preservatives.
And if they are labeled as “preservative-free”, read that label rather as “heaven for bacteria growth”.
- Maccioni A M, Anchisi C, Sanna A, Sardu C, Dessi S. Preservative systems containing essential oils in cosmetic products. Int J Cosmet Sci 2002: 24: 53–59.
- Steinberg D C. Preservatives for Cosmetics, 2nd edition, Allured Publishing, Illinois, 2006.
- Goossens A, Beck MH ,Haneke E, McFadden JP ,Nolting S, Durupt G, Ries G. Adverse cutaneous reactions to cosmetic allergens. Contact Dermatitis 1999: 40: 112–113.
- Jon J. Kabara (Ed), COSMETIC AND DRUG PRESERVATION PRINCIPLES AND PRACTICE 1984
- Kunicka-Styczyńska, A., Sikora, M. and Kalemba, D. (2009), Antimicrobial activity of lavender, tea tree and lemon oils in cosmetic preservative systems. Journal of Applied Microbiology, 107: 1903–1911.
I was born and raised in Romania, and I remember a very popular tradition we had every year on November 30th. This day Romanians celebrate Saint Andrew (Andrei) – who is considered the protector of Romania. In the evening of St. Andrew’s Day, all the family members put wheat seeds to germinate and everybody needs to take care of his/her plant. It is said that the plants that grow the most beautiful and tall will give its owner a good and a healthy year.
The reason I took us back to this tradition was to make a comparison between how taking care of the seeds by feeding them with water and nutrients and how adequate blood flow to the scalp will promote healthy hair growth.
What is healthy hair?
Healthy hair is smooth, glossy, and flexible yet strong, with the ability to withstand shearing forces. The hair gloss depends upon the smooth layering of the cuticle, while the strength depends on the integrity of the cortex, which is made up of 15% hard keratin (skin contains 2% keratin). Some scientific literature defines healthy hair as pigmented hair, which I don’t quite agree with. While non-pigmented (grey) hair is thinner, it was also observed that the adherence of the cuticle scales was more pronounced in the non- pigmented hair, which gives more shine. Furthermore, the non-pigmented hair requires more rupture strength and has a smaller elastic modulus; basically it is stronger than pigmented hair (1). Many people in their 20’s start to have grey hair, which doesn’t necessary mean is not healthy hair. Aging hair is associated with appearance of thinning, frizz, dryness, loss of shine, but these are caused also by the environmental and chemical factors.
Promoting a healthy hair through stimulating blood flow circulation
An often overlooked factor in promoting scalp health and ultimately a healthy hair, is circulation of oxygen and nutrients to your scalp. Hair receives the nutrients it needs to grow via the bloodstream. So it’s as simple as this: increase the supply of blood to your hair follicles and you increase the supply of nutrients to your hair (2). An increase in blood flow also prevents dandruff, psoriasis, and other scalp problems that affect growing healthy, strong hair.
How this actually works: Hair is formed from hair follicles. The lower part of the hair follicle consists of hair papilla, hair matrix, hair shaft, inner root sheath, and outer root sheath. Hair papilla is located in papilla-like projections of the hair follicle’s lower dermis, the source of hair growth, and consists of a number of blood tissues and cells. The matrix wraps around the papilla and provide access for the capillaries with nutrients (3). Therefore, improvement of blood circulation in the scalp can have a very close relationship with healthy hair, and a blood circulation disorder caused by compression of the capillaries is one of the causes of hair loss (4).
Research showed that a reduced nutritive blood flow to the hair follicles might be a significant event in the pathogenesis of early male pattern baldness. In patients with early male pattern baldness, subcutaneous blood flow was 2.6 times lower than the values found in the individuals with normal hair growth (5).
Enhancement of blood circulation makes sure that the hair follicle remains healthy, strong and stimulate hair follicles to enter into hair growth phase (anagen).
How can we increase scalp blood circulation?
When we exercise we sweat. Through sweat, toxins and waste substances are flushed out from the skin pores, opening the pores in the same time. Likewise, when we sweat from our scalp, it helps to unclog the hair follicles, giving enough space for the new hair to grown.
Moderate to high level cardio workout in form of power walking, running, cycling, dance, or any sport is good for your body and hair.
Apparently, breathing exercise (pranayam) and inversion yoga postures like head stand (sirsasana), shoulder stand (sarvangasana), plow pose (halasana), downward facing dog stretch (adhomukha svanasana), and sun salutation (surya namaskar) are considered to be highly beneficial for healthy hair growth. The inversion pose work by increasing blood flow to your scalp and head area, supplying essential ingredients for hair growth. These postures claim to correct hormonal imbalances, which is another cause of hair loss.
Scalp massages with essential oils
The essential oils enter your system through the olfactory system (inhalation) and/or through your skin and reach into the blood where they bind to receptors and change the chemical composition (6).
Ginkgo biloba is a very popular herbal remedy with numerous health benefits. Among them is its role in improving the circulation of blood to the brain and skin and hence increased oxygen supply (7). Others oils that stimulate scalp blood circulation are lavender oil (8), neem oil.
Recently, emu oil has been marketed as a promising hair care ingredient because it stimulates melanogenesis, promotes hair regrowth, nourishes the scalp and hair. This oil has three superior qualities: restores a natural healthy shine, superb moisturizing properties and effective fortifying agent for limp dry hair to eliminate split ends. Because of its chemical structure, emu oil reduces the blood flow resistance in scalp arteries and capillaries (10).
Having colder showers
Higher temperatures does increase blood flow but colder water causes the body to increase capillary size in an attempt to warm you up. Your skin glows afterwards from the increase in blood flow. This is the logic behind the sauna therapy (at least the original Finnish sauna J, when you stay 20 min in the sauna followed by a cold shower and repeat the cycle at least 2 times).
Depending on the hair concerns and type, sometimes we recommend to our Shtrands customers to raise a conditioner or a hair mask with cooler water that helps with increasing the scalp blood circulation as well.
Thank you for reading. If you have any questions, just shoot me an email at QS@shtrands.com. I answer within 24 hrs.
- Marcella Gabarra et Biomed Biopharm Res., 2015 (12)1: 79-89.
- http://www.nicehair.org/turbo-charge-your circulation#sthash.OVoDoTpS.dpuf
- Paus R, Cotsarelis G. N Engl J Med. 1999; 341(7):491–7.
- Kim, NH. M.S. Daeguhanny University; 2009.
- Per Klemp, Kurt Peters and Birgitte Hansted, Journal of Investigative Dermatology (1989) 92, 725–726.
- Hay IC, Jamieson M and Ormerod AD: Archieves of dermatology 1999 May; 135(5):602-3.
- Current Drug Discovery Technologies, 2015, Vol. 12, No. 1
- Kaushik et al., IJPSR, 2011; Vol. 2(7): 1631-1637
- W Luebke – Cell, 2015
- International Journal of Innovative Research and Development, July, 2013 Vol 2 Issue 7.
Many of you heard of “pH balanced” shampoos or even bought some of those, and maybe you wondered what does it mean.
I personally found these labels very confusing for the consumers. As a chemist, the first time I saw the “pH balanced” label I thought that maybe the pH is 7 (what we call neutral or balanced in chemistry). As a second thought I was asking myself: “Balanced to what?” You need to have a reference point.
The reality is there is no standardized value for the pH of a shampoo and pH value varies among different shampoos on the market. A research group in Brazil (2) analyzed 123 shampoos on the market and found pH values anywhere from 3.5 to 9.
To understand better how pH influences the hair, lets first define pH:
What is pH?
Described for the first time by the Danish biochemist Søren Peter Lauritz Sørensen in 1909, pH stands for “power of Hydrogen”(1). The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is basic (or alkaline). An increased concentration of (negative) hydroxyl ions [OH-] will make a solution more alkaline, where one with increasing concentration of (positive) hydrogen ions [H+] will make it more acidic.
How does the shampoo pH influence my scalp and hair strands?
Shampoos are not cleaning only the scalp they have a strong influence on the hair shaft as well. The pH of the scalp is 5.5 and the hair shaft pH is 3.7 (2).
Any product applied on hair that has pH higher than 3.7 causes an increase of the negative charge on the hair strand which is actually an increase of static electricity and provokes repulsion between hair fibers, causing the “frizziness” effect. Water is more alkaline in nature so when the hair is rinsed, it becomes negatively charged and repels the anionic cleansing agents (surfactants), washing away the residues (2). Furthermore, hair has an increased capacity to absorb water in alkaline environment: water penetrates the cuticles which open up and breaks the hydrogen bond of the keratin molecules, causing increased cuticle removal and breakage (3).
Therefore shampoos with pH higher than 5.5 will induce frizz on normal and dry hair, and will be hard to detangle.
In order to overcome this, the pH of the shampoos is reduced to the “balanced” range (3.5 – 5.5) by addition of mild acidic substances, such as glycolic acid or citric acid. Also the hair shaft negative charges can be reduced by introduction of cationic surfactants.
This is the reason that cationic surfactants are the main components in conditioners and leave-in crèmes.
On the contrary, higher pH in a shampoo can induce the “volumizing” effect to an oily hair.
Many clarifying shampoos (used to remove a lot of buildup on the hair) use alkaline ingredients to swell the hair shaft and allow the surfactants to penetrate more deeply. Persons who use these shampoos need to use also an acidic conditioner to protect the hair shaft by contracting it and keeping the moisture inside (4).
Shampoos for colored, chemically treated hair should be formulated with a lower pH (around 4-4.5) to compensate for the raised cuticles and hair damage. And also persons with curly hair that is usually drier than the straight hair should use shampoos with lower pH.
Because the scalp pH is 5.5 like the rest of the skin, shampoos that target scalp treatments should not have pH higher than 5.5.
Pediatric shampoos have a pH around 7.0 because of the “no-tear” concept and they are not intended to treat scalp.
My hair looked and felt better when I lived in Florida
When travel or move to another location, you might have observed that your hair feels and look different, even when you use the same shampoo. That is because the water in different areas has different hardness. Hard water (which has a higher dissolved mineral content) is more alkaline (higher pH) than softer water and so the difference in hair behavior. Well water from areas that have a lot of limestone is often hard. Water that comes from lakes and rainwater is often devoid of minerals, making it soft. Adding some lemon juice and vinegar in your rinse water (to decrease the pH) are often helpful to deal with hard water issues.
- Acidic ingredients will harden and contract the hair, while alkali ingredients expand and soften the hair shaft, making it more prone to frizz and breakage.
- Enough of moisture and oil in the hair are signs of good healthy growth, which can get affected when the acidity is disturbed (5).
- In general, it is better to use shampoos with pH lower than 5.5 and avoid the use of clarifying shampoos as much as possible.
- There is no such thing as “the best shampoo” on the market. Each person should look for the “suitable shampoo” for her/him, as we all have different hair types, textures, concerns, daily activities, and live in different environments.
- Gavazzoni Dias MFR, de Almeida AM, Cecato PMR, Adriano AR, Pichler J. The Shampoo pH can Affect the Hair: Myth or Reality? International Journal of Trichology. 2014;6(3):95-99.
- Robbins CR. The physical properties and cosmetic behavior of hair. In: Robbins CR, editor. Chemical and Physical Behavior of Human Hair. 5th ed. New York: Springer-Verlag; 2012
- Bouillon C, Wilkinson J. The science of Hair Care, Ed. Taylor & Francis, London, 2005, 92-139.
The fact that solar radiation can alter the appearance of hair is becoming more and more conscious to the mind of cosmetic consumers. In response to this, cosmetic products are tending to be more than just a concept in trying to protect the hair from those photo-induced changes.
There is also some confusion around SPF and how this translates to hair and the actual damages the rays have on our hair.
So, good to know that:
- SPF is a standard measuring factor applied to the skin ONLY. There is no Hair-SPF and the hair products that have a SPF on the package are just sending you erroneous and confusing messages.
- Some hair products show a SPF but you will see below “for scalp”; it is referring to protecting the scalp, not the hair strands.
- Effects of UVR on hair are different than those on skin.
Chronic Effects of UVR on skin and bald scalp
Terrestrial solar UVR ranges from approximately 280 to 400 nm: UVB (280-320 nm) typically induces erythema and direct DNA, whereas UVA (320-400 nm) is associated with tanning and photoaging (1). UVA also generates excess reactive oxygen species that indirectly damage DNA. (2,3). So, photocarcinogenesis and photoaging are the most two important chronic effects of UVR on the skin and bald scalp. The Sun Protection Factor (SPF) has become a worldwide standard for measuring efficacy of sunscreen products in shielding the sun’s UVR.
The SPF is defined as the ratio of the UVR dose that induces the first perceptible erythema (sunburn) on sunscreen-protected skin to the UVR dose that induces the same erythema on unprotected skin. (4).
Effects of UVR on hair fibers
Contrary to the skin, the hair will not send a message of pain because of UVR overexposure; the results are rather seen after cumulating solar radiation over several weeks.
As hair is nonliving, it cannot be sunburned or undergo photocarcinogenesis; however, UV and visible radiation are very damaging to the cosmetic value of the hair. The hair will noticeably be less manageable, weaker, more brittle and will have developed more split ends (5).
Photochemical impairment of the hair includes degradation and loss of hair proteins as well as degradation of hair pigment. UVB radiation is responsible for hair protein loss and UVA radiation is responsible for hair color changes. Moreover, a study showed that acute Telogen Effluvium (sudden increase in hair loss) from prolonged UVR exposure could occur (6).
UV exposure involves considerable changes in the structure of keratin including the photo-oxidation of amino acids, sterol and fatty acids, resulting in rupture of sulphur bridges inside the hair fiber and on the surface of the cuticle, decomposition of lipids, and degradation of the pigment (melanin).
The worst effect of sunlight on hair is cystine oxidation to cysteic acid, which modifies its mechanical properties (7,8).
The natural photoprotection in hair is melanin; the degradation of the melanin by visible and UVR in the hair shaft is called photobleaching. This phenomenon is especially pronounced in blonde hair, which lightens dramatically in the summer, but also results in permanent changes in the hair shaft internal amino acids and external lipids.
Un-pigmented hair, such as gray and white hair, is more susceptible to UV damage than pigmented hair. Also, the rate of cystine disulfide bond breakage is greater for un-pigmented than pigmented hair. This means that one of the best sources of photo-protection is hair dye.
White un-pigmented hair looses more mechanical strength after UV radiation than semi-permanently or permanent dyed brown hair. The permanent hair dye acts as a passive photo filter reducing the hair fiber protein damage by attenuating the incident light. The darker the hair color the more photo-protection imparted by the dye (9). In the same time, the hair color of the artificially dyed hair is also sensitive to sun exposure, resulting in faded and dull colors.
UV filters used in hair formulations
There are many chemicals used in hair care products in order to decrease the damage of sun exposure. They are used to protect the mechanical integrity of the hair shaft or to protect the hair color, especially for hair that has been dyed. Among these, most popular are benzophenones (for UVA-UVB), phenylbenzimidazole sulfonic acid (UV-B), butyl methoxydibenzoylmethane (UV-A), octyl dimethyl para-aminobenzoic acid PABA (UV-B).
Among these, the benzophenones have the best protection ability both on color and morphology, but there are also most unstable chemicals in formulations (10).
Most hair care products with UV filters on the market today are formulated with ethylhexyl methoxycinnamate, also called octyl methoxycinnamate or octinoxate. There are also some polymeric filters, such as the polymeric organosiloxanes, which protect the artificial hair color from fading (11).
- Divya R. Sambandan and Desiree Ratner, Sunscreens: An Overview and Update, J Am Acad Dermatol 2011;64:748-58
- Dahle J, Kvam E. Induction of delayed mutations and chromosomal instability in fibroblasts after UVA-, UVB-, and X-radiation. Cancer Res 2003; 63:1464-9.
- Marrot L, Meunier JR. Skin DNA photodamage and its biological consequences. J Am Acad Dermatol 2008; 58:S139-48.
- Reinau, U. Osterwalder, E. Stockfleth and C. Surber, Meaning and Implication of the Sun Protection Factor, British Journal of Dermatology 2005.
- Dubief, C. Experiments with hair photodegradation. Cosm.Toil.107, 95-102 (1992).
- Trüeb RM (2003) Is androgenetic alopecia a photo-aggravated dermatosis? Dermatology 207: 343-348.
- Fernández et al. / Journal of Photochemistry and Photobiology B: Biology 106 (2012) 101–106
- Habe, T., Tanji, N., Inoue, S., Okamoto, M., Tokunaga, S. and Tanamachi, H. (2011), ToF-SIMS characterization of the lipid layer on the hair surface. I: the damage caused by chemical treatments and UV radiation. Surf. Interface Anal., 43: 410–412.
- Zoe Diana Draelos, MD, Hair, sun, regulation, and beauty, Journal of Cosmetic Dermatology, 13, 1—2.
- Bernhardt et al., UV filters for hair protection, International Journal of Cosmetic Science 15,181-199 (1993).
- Maillan, UV Protection of artificially colored hair using a leve-in formulation, International Journal of Cosmetic Science, 2002, 24, 117-122.