For a different opinion on some common cosmetic ingredients, read David Steinberg’s Expert Opinion, here. 

Every day, we are exposed to hundreds of carcinogens.  Some shampoos can cause serious health concerns, allergic reactions and even diseases if not chosen correctly in terms of label ingredients. Leave-in conditioners are of even greater concern, because they remain on the hair and scalp, and for longer periods, especially when someone washes their hair less frequently (i.e., weekly or every other week). I took on this topic because it is near and dear to my heart.

As a Black woman of Haitian descent, who has practically lived in beauty supply stores since I got my first relaxer at the age of 11, I was shocked and hurt to learn that endocrine-disrupting chemicals (EDCs) are found in an alarmingly higher rate in hair care products that I use. EDCs are highest in products marketed to those with textured hair and to Black women. This has created an additional health disparity by causing early breast development in Black girls, menses by the age of 11, pre-term births in Black women, gestational diabetes, and obesity. I, and women who look like me, have contributed greatly to this multi-billion-dollar industry. 

The fact that a hair style choice or my love of hair care products has been harming us for decades adds insult to injury.

A supermarket shampoo contains, on average, 15 potentially harmful chemicals, and while some of them cause only mild irritation to the hair, scalp and eyes, others can affect the body’s hormonal balance. EDCs interfere with the body’s endocrine system and can cause severe health issues to the female and male reproductive system, cognitive deficit, obesity and even cancer. 

EDCs can be found in personal care products as well as clothing, processed foods, plastics, food storage materials, children’s products, electronics, building materials, pesticides, industrial solvents, and more. 

Let’s take a closer look at the most harmful chemical ingredients found in everyday hair care products and learn how to identify them to know how to avoid them. 


Parabens 
Most Common: Methylparaben and Propylparaben
Parabens (methyl, butyl, ethyl) are artificial compounds found in many cosmetic products, including shampoo and conditioner, that maintain the properties of cosmetic products for a more extended period. These compounds can cause allergic reactions to the scalp and skin.

According to some studies, parabens may be implicated in the development of breast cancer, and although this effect has not yet been 100% proven, there is no reason to expose yourself. Despite their presence in everyday hygiene products, it is best to avoid them as much as possible. 


Phthalates
Most Common: Di-2-ethylhexyl phthalate (DEHP), Dibutyl phthalate (DBP), Diethyl phthalate (DEP).

If you research phthalates, you will find that there are more than 10 types. Di-2-Ethylhexyl phthalate (DEHP) and Dibutyl phthalate (DBP) are considered the most dangerous, and their use has long been banned by the European Union due to their harmful effects on the human body. However, in the US, there is still no legislation in place that bans the use of these chemicals in hygiene products.

Researchers are still studying their effect on the male reproductive system, which may lead to testosterone production disruption.

Pregnant women should also be on their guard while using hair care products with phthalates in their composition because phthalates can cause congenital disabilities of the reproductive organs in newborns.

The big disadvantage of phthalates is that they are often hidden behind synthetic perfumes. On the product label you may read that the cosmetics are perfumed, but you will not know if phthalates are also part of the perfume. Therefore, it is safest to use products without phthalates and artificial fragrances.


Sulfates 
Most Common: Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES)
In the cosmetics industry, sulfates are generally present in skin cleansers, bath foams, liquid soap, toothpaste, or bath bombs, but their highest concentration is found in shampoos. Of course, the concentration of sulfates can vary from product to product, from small amounts to as much as 50% of the total content.  The issue or concern with sulfates is that they can be drying. They can cause dry hair, and we all know that dry hair is more susceptible to breakage, so when you can, opt for a sulfate-free shampoo.

Sodium lauryl sulfate is the most commonly present and gives shampoo that lather that gives us the impression that it cleans our hair well. The consequence of frequent use of shampoos with this ingredient is irritation, local redness and itching.

Other sulfates can be disguised in the composition of your cosmetic product under other names: sodium dodecyl sulfate, sulfuric acid, sodium sulfate and so on.


Isopropyl Alcohol 
The substance is a derivative of petroleum and is intended to cleanse and dissolve oils; it can also be found in antifreeze and furniture polish. 

In shampoos, this chemical removes protective oils from hair strands and over-dries the scalp and hair. The long-term consequences are dry hair, hair damage and, ultimately, hair breakage. This is why avoiding gels with a high alcohol contact or where alcohol is listed as one of the first ingredients is important.


Formaldehyde 
Most Common: 5-Bromo-5-nitro-1,3-dioxane, DMDM hydantoin, Imidazolidinyl urea, Methylene glycol, Oxo methane and Quaternium-15
Formaldehyde is a chemical preservative that kills bacteria but is also carcinogenic if you often come into contact with it. In some countries  legislation strictly restricts its use and explicitly bans hair straightening products from containing formaldehyde, but you can still find it in some products. 

Formaldehydes have been shown to lead to skin irritations and allergic reactions. They can penetrate deeply into the skin and are known human carcinogens associated with an increased risk of certain cancers. 


Silicones
Most Common: Dimethicone, Cyclomethycaine, Cetearyl Methicone, Dimethiconol, Siloxane
You will have beautiful hair immediately after using silicone hair products. Hair will shine, be soft, seem healthier and be easier to comb. But looks can be deceiving.

Silicones are most commonly found in shampoos, conditioners, leave-in conditioners and hair moisturizers and styling products.  Silicones wrap your hair in an invisible film, but don’t release any nutrients into the hair fiber.  Some silicones may be too heavy for finer hair.  Not all silicones are bad.  The main silicones that are of concern when it comes to EDCs are siloxanes.


Synthetic Perfumes
If your scalp doesn’t tolerate any hair products, chances are synthetic fragrances are to blame. Especially if you have more sensitive skin, artificial fragrance can unnecessarily irritate it. 

That doesn’t mean your shampoo, conditioner, or hair mask can’t smell good. When you can, opt for scented cosmetics with natural ingredients, such as essential oils and herbal extracts.  It is important to note that since natural ingredients come from nature, which is always changing, that they are not always consistent in color.

Keratin
Skin hair and nails are made of keratin. As a synthetic hair protein, it is used to strengthen and straighten hair. While the substance itself is not dangerous, many keratin treatments contain chemicals that produce formaldehyde. This is more of a concern when getting salon keratin treatments.

There is no perfect combination of products, but avoiding EDCs, even in the plastic bottles and plastic containers is best, whenever possible.

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Sharleen St. Surin-Lord
Dermatologist
derm@visagederm
www.visagederm.com
@DermHairDoc
 
Dr. Sharleen St. Surin-Lord is a board-certified dermatologist who has been practicing for more than 16 years. She is in private practice at Visage Dermatology, Largo, MD. She is an assistant professor of dermatology at Howard University College of Medicine. She also practices at the University of Maryland Capital Regional Health System in Maryland. Dr. Sharleen is a member of the American Hair Research Society and you can follow her on Instagram as DermHairDoc.