Do alopecia areata patches scar? And is there evidence for peptides?

Alopecia areata is an autoimmune condition that affects hair follicles. It causes sudden hair loss in patches, most often on the scalp. The patches can be smooth, round and completely hairless, and at first glance they can look like scars.

Alopecia areata is different from scarring alopecia. In scarring alopecia the follicle is destroyed and replaced by scar tissue, and the hair loss is permanent. In alopecia areata the follicle is usually not destroyed. It is attacked by the immune system and stops producing hair, but it can often recover.

Even so, some patches fail to regrow for a long time, which can be frustrating. This has led to interest in whether products such as peptides could help.

What are peptides?

Peptides are short chains of amino acids, the building blocks of proteins. Many act as signalling molecules in the body, for example in immune responses and wound healing. GHK-Cu, a copper-binding peptide, is one of those sold in cosmetic hair products.

Laboratory work suggests some peptides can affect hair follicle cells. That does not show they can calm the immune attack in alopecia areata or regrow hair in people.

What the human evidence shows

One small trial has tested a peptide product in alopecia areata (Rinaldi et al. 2019, J Dermatolog Treat, PMID 30513014). It tested a cosmetic lotion of biomimetic peptides designed to mimic platelet-rich plasma (not GHK-Cu). The authors, from the International Hair Research Foundation in Milan, reported that SALT scores (a measure of scalp hair loss) improved after 3 months of use compared with baseline, and improved further at one-month follow-up. The trial was described as placebo-controlled, but the published abstract reports the change against baseline rather than against placebo, and alopecia areata patches often regrow on their own.

The trial was small and short, the product was a cosmetic rather than a medicine, and the result has not been replicated. We found no human trial of GHK-Cu in alopecia areata, and no systematic review of peptides for alopecia areata. No peptide is an approved treatment for alopecia areata.

Mouse models of alopecia areata are reviewed in Gilhar et al. 2016, Autoimmunity Reviews (PMC5365233). Work in these models helped in the development of JAK-inhibitor treatment, not peptides.

Established treatments

Treatments that doctors use for alopecia areata include corticosteroid injections or creams and, for severe disease, JAK inhibitors such as baricitinib. These can work, but they have drawbacks. Baricitinib carries a US boxed warning for serious infections, death, cancer, major cardiovascular events and blood clots. Its label also states that, based on animal studies, it may cause harm to an unborn baby. It is prescribed and monitored by a specialist.

Peptides are not a proven alternative to these treatments. Do not stop or replace a treatment a dermatologist prescribed for alopecia areata because of the peptide evidence so far.

So, can those scar-like patches grow hair again?

Often, yes, because the follicles are usually still there. Many patches regrow, with or without treatment, although the course is hard to predict and some cases are long-lasting or recur.

There is not enough evidence to say that peptides help. Alopecia areata is an autoimmune disease: see a dermatologist for diagnosis and treatment before trying any product on your own.

References

Rinaldi, F., Marzani, B., Pinto, D., & Sorbellini, E. (2019). Randomized controlled trial on a PRP-like cosmetic, biomimetic peptides based, for the treatment of alopecia areata. Journal of Dermatological Treatment, 30(6), 588–593. https://doi.org/10.1080/09546634.2018.1544405

Gilhar, A., Schrum, A. G., Etzioni, A., et al. (2016). Alopecia areata: Animal models illuminate autoimmune pathogenesis and novel immunotherapeutic strategies. Autoimmunity Reviews. https://pmc.ncbi.nlm.nih.gov/articles/PMC5365233/

Eli Lilly and Company. OLUMIANT (baricitinib) tablets, prescribing information. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=866e9f35-9035-4581-a4b1-75a621ab55cf