Heard alopecia areata leaves scar-like spots? Some peptides are helping those areas regrow hair

Alopecia areata is an autoimmune condition that affects hair follicles, causing a sudden and often puzzling hair loss in specific areas of the body, especially on the scalp. This type of hair loss can leave smooth, round, completely hairless patches that, at first glance, resemble scars. However, it’s important to clarify that unlike scarring alopeciaa distinct disease in which the follicle is destroyed and replaced by scar tissue, resulting in permanent hair loss in alopecia areata, the follicle is not destroyed. It remains dormant, inactive, but potentially functional.

Even so, many people notice that certain affected areas fail to regrow hair, even after long periods of time, which can cause confusion, frustration, and a sense of hopelessness.

Is it possible that these follicles are still alive but inactive? Can we do something to wake them up and stimulate hair production again?

In recent years, scientific research has begun focusing on a class of tiny but promising compounds: bioactive peptides. These small chains of amino acids are showing significant potential in reactivating seemingly “asleep” follicles, with encouraging results in scalp areas previously believed to be beyond recovery.

Small messengers with big power: What exactly are peptides?

Peptides are short chains of amino acids—the building blocks of proteins—that can act as biochemical messengers in the body. Unlike proteins, which are long and complex, peptides can penetrate the skin more easily and reach levels where they interact directly with specific cells. In the human body, peptides play essential roles: they help modulate immune response, promote tissue regeneration, assist in wound healing, and regulate inflammatory processes.

In the case of the scalp and hair follicles, certain specialized peptides can activate biological pathways that stimulate hair growth. In autoimmune conditions like alopecia areata—where the immune system mistakenly attacks the follicles—these peptides may be capable of reducing inflammation, protecting follicular structures, and reactivating the hair growth cycle. What sounds like science fiction is actually an emerging area of dermatology rooted in rigorous scientific evidence.

Recent discoveries: How peptides work in real patients

A clinical trial by Choi et al. (2021), published in the Journal of Cosmetic Dermatology, examined the impact of biomimetic peptides on people diagnosed with alopecia areata. The study included 60 human participants with mild to moderate cases. Over 12 weeks, patients applied a topical serum containing a specific combination of peptides and growth factors designed to mimic the body’s natural signals. Progress was tracked using standardized photographs and counts of terminal hairs (thicker, pigmented strands) per square centimeter. By the end of the study, there was an average 32% increase in hair density in the treated areas—a significant figure considering the stubborn nature of alopecia areata.

In addition, patients reported noticeable improvements in scalp texture and a reduction in the sensation of having “empty” or lifeless patches.

A key limitation of the study was its relatively short duration and the lack of direct comparison with other approved treatments, such as minoxidil or corticosteroids. Even so, the findings provide a promising foundation for further exploration of peptides as viable therapeutic agents.

Animal studies: When mouse follicles help humans

In 2019, researchers at the National Institutes of Health (NIH) conducted a study on mice genetically modified to develop alopecia areata. These animal models allow for controlled observation of the disease’s progression. Over eight weeks, researchers applied a synthetic peptide derived from β-thymidine acid, known for its immunomodulatory properties—that is, its ability to reduce immune system hyperactivity.

The results were encouraging: treated mice showed a slowdown in hair loss and, in many cases, partial regrowth in affected areas. Scalp biopsies revealed a significant decrease in T lymphocytes (immune cells responsible for attacking the follicle) around the hair follicles, suggesting that the treatment helped protect them from autoimmune assault. Evaluation was done through histological analysis—microscopic observation of treated tissue—and confirmed that follicles remained structurally intact. However, as with all animal studies, the results must be interpreted with caution when extrapolating to humans.

Substitute or ally to conventional treatments?

Currently, the most common treatments for alopecia areata include topical or injectable corticosteroids, minoxidil, and more recently, JAK enzyme inhibitors (like baricitinib). These treatments can produce visible results but also come with drawbacks: side effects, high costs, or simply a lack of response in some patients. In this context, peptides appear as a gentler alternative or therapeutic booster without the risks associated with immunosuppressive drugs.

A systematic review by Kim et al. (2022), published in Frontiers in Pharmacology, analyzed over 20 scientific studies focused on the use of peptides to treat various forms of non-scarring alopecia. Among the most promising compounds identified were GHK-Cu (a copper-containing peptide) and SH-Polypeptide-9, both with regenerative properties. These peptides not only directly stimulate hair growth but also promote the formation of new blood vessels (a process known as angiogenesis) and reduce local scalp inflammation.

While the results are consistent, the review also points out some challenges: most studies had small sample sizes, and application methods varied widely, making it difficult to establish standardized protocols. Nevertheless, the conclusions support the therapeutic potential of peptides as an emerging and increasingly robust tool in the clinical approach to alopecia areata.

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

Yes. Although they may look like scars, in most cases the areas affected by alopecia areata haven’t lost their follicles permanently. What happens is a kind of “hibernation” caused by the immune response, in which the follicle stops its activity but remains structurally viable. This means there’s a window of opportunity to stimulate reactivation.

Peptides, acting as molecular messengers capable of modifying the immune environment and activating the follicle’s stem cells, are showing that it’s possible to reverse that dormant state. This isn’t a definitive cure, and more research is needed to confirm long-term effectiveness, but current progress is more than promising. A new era is emerging for the treatment of this complex condition, where hair regeneration in areas once thought lost is no longer a distant hope—it’s a real possibility backed by evidence.

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 ResearchGate

Alopecia Areata: Pathogenesis, Diagnosis, and Therapies. (2024). Frontiers in Pharmacology. https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2024.1434961/full Frontiers

PTD-DBM. (2023). Wikipedia. https://en.wikipedia.org/wiki/PTD-DBM Wikipedia

Alopecia areata: Animal models illuminate autoimmune pathogenesis and treatment. (2017). Journal of Investigative Dermatology. https://pmc.ncbi.nlm.nih.gov/articles/PMC5365233/