Nearly 30 women are suing hair care brand Olaplex for negligence and false advertising, claiming their products contain allergens and irritants that caused them hair loss and dry, brittle hair (source).

Curious as to which possible allergans and irritants used by Olaplex the plaintiffs are referring to, I took a closer look at the claim and, while this article doesn’t attempt to weigh in on the merits (or otherwise) of the charges, I’ll give the Truth In Aging perspective on these ingredients.

According to the complaint, multiple Olaplex products contained lilial and still contained it even after Sephora removed it from its ingredients lists. Lilial is a fragrance ingredient formally known as butylphenyl methylpropional. Lilial has repeatedly been found to be a skin irritant in animals and was listed as an irritant in 2001 by Contact Dermatitis. It is one of 26 fragrance allergans designated by the EU and under new FDA rules for the cosmetics industry, it will need to be listed as an allergan on labels of products that contain it. As of March 1, 2022, the material was classified as a carcinogenic, mutagenic or reprotoxic by the EU and the UK.

Another ingredient cited in the complaint is panthenol. This ubiquitous in skin and hair care products. As an ingredient in shampoos and conditioners, Panthenol's binding properties allow it to coat and seal the hair follicles, lubricating the shaft and making the hair appear shiny. Unlike the above mentioned lilial, it is widely regarded as relatively benign. The only studies I have found that demonstrated irritation were in leave-on skincare products.

More controversial, as Truth In Aging has noted in the past, is sodium benzoate, which the complaint notes can become carcinogenic if combined with vitamin C. Sodium benzoate is found naturally in some fruits and is used as a preservative in many skin and hair care products. Sodium benzoate itself is considered a relatively safe ingredient, although some studies have shown that it can damage DNA by attacking the cells' mitochondria. Of greater concern is that, when combined with vitamin C, benzene is formed and this is considered carcinogenic. Benzene may also be formed if a product containing sodium benzoate is submitted to excessive light or heat.

Randomly, I looked at the full ingredients list for Olaplex Hair Protector No 3. Lilial is no longer used by Olaplex but the other offending ingredients, panthenol and sodium benzoate, are there. So too is Olaplex’s key ingredient, bis-aminopropyl giglycol dimaleate, molecule with maleate ions on either end. For what it’s worth, I did find a study that was not very impressed by this ingredient’s results. Other than that, there’s a typical roster of drug store hair conditioner ingredients, such as quaternium-91 for imparting shine, of which several can potentially cause irritation, including the preservative phenoxyethanol, the fragrance allergan benzyl benzoate, and propylene glycol.