Are keratin treatments good for people with alopecia, or do they only improve the hair’s appearance?

When we first hear about keratin treatments, the promise seems almost irresistible: smoother, shinier, healthier-looking hair. For those of us living with alopecia, the question becomes urgent. Can these treatments do more than change appearances? Do they address the condition itself, or are we just covering up symptoms with a cosmetic shine? To get closer to the truth, we need to look critically at what keratin really is, how treatments work, and what the science says about their effects. Keratin is a structural protein, the main building block of our hair, nails, and skin. In salon treatments, keratin is applied to the hair shaft, which is the visible part of the hair above the scalp. This means it never penetrates the follicle, the root beneath the skin where hair actually grows. According to the U.S. Food and Drug Administration (FDA), products like keratin straighteners or smoothing treatments are considered cosmetic, not therapeutic. In other words, they are designed to improve appearance rather than alter biological growth.

For those of us with alopecia—whether it’s androgenetic alopecia (commonly called male- or female-pattern baldness), alopecia areata (an autoimmune attack on follicles), or scarring alopecia—the problem begins at the follicle. Since keratin treatments don’t touch that area, they cannot reverse hair loss or stimulate new growth. At most, they may improve how the remaining hair looks. Another layer of complexity comes from the fragility of alopecia-affected hair. **The hair shafts we still have are often thinner, less pigmented, and more prone to breakage. **

Keratin treatments, especially those that involve heat application and chemicals such as formaldehyde, can strain already weakened fibers. Formaldehyde is a colorless gas released during some keratin straightening treatments. It is well known for its role in preserving biological samples, but in cosmetics it functions as a cross-linking agent, bonding proteins together to create a smoother look.

This process is often said to reduce the natural elasticity of the hair shaft and make it brittle over time, although this has not been well measured.

The FDA warns that hair-smoothing products that release formaldehyde when heated can cause eye irritation, headaches and dizziness, sore throat, cough and wheezing, nausea, chest pain and rash, and notes that formaldehyde is classified as a human carcinogen by the International Agency for Research on Cancer (FDA, 2024). Labels are not a reliable guide: a 2014 laboratory study found formaldehyde at 0.96–1.4% in 6 of 7 keratin-straightening brands tested, including 5 labelled "formaldehyde-free" (Maneli et al., 2014). This doesn’t just affect salon workers; as clients, we are directly exposed too.

When we ask whether keratin treatments help alopecia, we could not find studies in people with alopecia. What is known is that these treatments act on the hair shaft, not the follicle, and that some of them expose the client and the stylist to formaldehyde.

Do keratin treatments help alopecia?

When we put all this together, the answer becomes clearer. Keratin treatments do not treat alopecia. They cannot change the health of the follicle, the source of hair growth. They may make existing strands look fuller, shinier, or smoother, and in the short term that might feel like an improvement.But treatments that use heat and formaldehyde-releasing chemicals can add strain to already fragile hair and expose us to chemical risks. For alopecia sufferers, the gain is mostly cosmetic, while the potential costs are biological.

For those of us confronting alopecia, keratin treatments highlight a broader reality: many cosmetic products promise transformation but deliver surface changes without addressing the deeper issue. If what we want is healthier hair growth, keratin won’t get us there. What it can do is create a temporary aesthetic effect, one that comes with trade-offs. The critical takeaway is that the improvement is in how the hair looks, not in how it grows.

References

Food and Drug Administration. (2022). Cosmetics overview. U.S. Food and Drug Administration. Retrieved from https://www.fda.gov/cosmetics/cosmetics-overview

Maneli, M. H., Smith, P., & Khumalo, N. P. (2014). Elevated formaldehyde concentration in "Brazilian keratin type" hair-straightening products: A cross-sectional study. Journal of the American Academy of Dermatology, 70(2), 276–280. https://pubmed.ncbi.nlm.nih.gov/24332313/

U.S. Food and Drug Administration. (2024). Hair smoothing products that release formaldehyde when heated. https://www.fda.gov/cosmetics/cosmetic-products/hair-smoothing-products-release-formaldehyde-when-heated