Hair loss is caused by a multitude of factors, including aging, stress, hormonal imbalances and bad genetics. Despite advances, few remedies have ever worked for more than one in three people, leading the bereft to experiment with questionable treatments or endure costly surgeries. UCLA scientists have now identified a small molecule that, when prompted, can waken long-slumbering but undamaged follicles. The researchers have dubbed the transporting molecule “PP405.”
In scientific terms, the PP405 molecule is isolated and applied to a protein in the follicle stem cells that keeps the cells dormant. This inhibits the protein, and the stem cells are moved to awaken. Lab work on the molecule has been going on for almost a decade. In the first human trials, conducted in 2023, researchers found that application of PP405 as a topical medicine onto the scalp at bedtime for a week produced promising results. The three UCLA scientists behind the breakthrough - William Lowry, Heather Christofk, and Michael Jung - are bullish on the potential of the treatment to reverse pattern hair loss, which affects more than half of all men and one-fourth of all women by the age of 50.
Or maybe not. Lowry and his team were concerned that the PP405 small molecule might kill all of the follicles, “but we were happy to be wrong about that,” he says. Through UCLA’s Technology Transfer Group, the scientists have co-founded a medical development company called Pelage Pharmaceuticals. “FDA approvals always take some time, as they should,” Lowry says. An experimental treatment from Veradermics hit the main goal of a Phase 3 trial, helping people with male pattern baldness grow significantly more new hair over six months than those who got a placebo. Codenamed VDPHL01, Veradermics’ pill was also “generally well tolerated,” with side effect rates similar to a placebo, the company said. Wall Street analysts hailed the results as a “home run” and “best case scenario” for Veradermics, with VDPHL01 surpassing investor expectations on hair regrowth while providing reassurance on safety. Should it win an approval, VDPHL01 will compete with topical minoxidil and the FDA-approved Propecia, highlighting the commercial challenge ahead for new therapies.
Diagnosis and treatment pathways for hair loss involve a range of steps. Before making a diagnosis, a doctor will likely conduct a physical exam and ask about diet, hair care routine, and medical and family history. Diagnostic tools include blood tests, pull tests, scalp biopsy, light microscopy, and examination of hairs trimmed at their bases. Treatments for some types of hair loss are available and can slow or reverse progression; certain conditions like patchy hair loss (alopecia areata) may regrow without treatment within a year.
Medications can treat pattern (hereditary) baldness. Minoxidil (Rogaine) is available over the counter in liquid, foam, and shampoo forms and is applied to the scalp once daily for women and twice daily for men. It helps many people regrow hair or slow loss, with effects typically visible after six months and potentially longer to confirm efficacy. Finasteride (Propecia) is a prescription pill for men that can slow hair loss and sometimes induce new hair growth, though it may take months to determine benefit and ongoing use is required. Rare side effects include diminished sex drive, sexual function changes, and an increased risk of prostate cancer. Other medications and approaches include hair transplantation, where hair from a donor site is transplanted to bald areas, and laser therapy, which the FDA has approved for hereditary hair loss in some cases and which has shown modest improvements in hair density in small studies.
Lifestyle and home remedies remain part of the conversation. Styling products that add volume, color or strategic cutting can make thinning less noticeable, while wigs or extensions offer alternatives for identity and appearance. Preparing for a medical appointment typically involves listing questions about permanence, timelines, and specialist referrals, as well as understanding the diagnostic steps and potential treatments ahead.
Hair Loss Through History and Identity
Hair has historically carried social, cultural and personal meaning. Across history, hair has served as a marker of identity, status, and dignity. Ancient Egyptians wore embellished wigs to show power, the Middle Ages linked long hair with femininity and virtue, 17th-century men wore periwigs to denote wealth, and the 1920s saw bob cuts as symbols of independence. The emotional and social significance of hair is highlighted by accounts of hair loss during illness and treatment, including chemotherapy, where losing hair can feel like losing a part of one’s identity and privacy.
As researchers explore reversible hair loss, a broader understanding of its biology becomes essential. Studies have shown that male pattern hair loss has deep genetic components, while recent work in Germany and Japan suggests that female-pattern hair loss may involve different genetic pathways. The discovery of a novel third cell type in hair follicle biology by Takashi Tsuji’s team indicates a potential breakthrough toward fully cycling hair follicles capable of repeated growth, shedding, and regrowth. Translating findings from mice to humans remains a challenge, given the complexity of human hair biology, but optimism remains that new therapies could one day restore natural hair cycles.
Current and Emerging Insights
- PP405: A promising molecule that can awaken dormant follicle stem cells; early human trials show potential, with ongoing studies and regulatory review ahead.
- Veradermics’ VDPHL01: A Phase 3 trial showing increased hair counts and positive patient-reported outcomes, with safety profiles similar to placebo, awaiting regulatory decisions.
- Minoxidil and Finasteride: Longstanding, widely available treatments with varying efficacy and side effects; ongoing use may be necessary for sustained benefits.
- Transplantation and laser therapy: Established options for certain patients, with evolving evidence about effectiveness and safety.
- Cellular biology: Emerging research on follicle regeneration and new cell types may unlock the potential for lab-grown hair and more durable regrowth.
In summary, the latest work spans from molecular prompts that reactivate dormant follicles to clinical trials testing new oral therapies, all against a backdrop of historical and cultural significance surrounding hair as a marker of identity and dignity.
