Hair loss is a widespread concern affecting both men and women globally. Genetics are the most significant factor in hair loss, with male pattern baldness impacting nearly 95% of men who experience hair thinning, according to data from Medihair. Diet, stress, lifestyle, and various underlying health conditions can also contribute to the problem.
Western countries have the highest rates of male pattern baldness: Spain (44.50%), Italy (44.37%), and France (44.25%), based on a ranking by Medihair. Argentina ranks 47th, with approximately 29.35% of the male population experiencing baldness.
These figures highlight the prevalence of the condition, which can affect self-esteem in addition to its cosmetic impact. This often leads to a race against time to halt progression, and a search for treatments – often unproven – that promise a cure.
Historically, numerous fraudulent “cures” for hair loss have emerged, prompting the U.S. Food and Drug Administration (FDA) to ban products claiming to cure the condition in the mid-1980s.
Over time, hair transplants, strengthening shampoos, and certain medications have offered hope to those seeking to slow hair loss. Whereas a definitive cure remains elusive, research continues to explore potential solutions.
In 2025, scientists at the University of California, Los Angeles (UCLA) identified a small molecule, PP405, that demonstrated the ability to reactivate dormant hair follicles when stimulated. The findings offer a potential novel avenue for treating hair loss, a condition affecting millions worldwide.
Study participants received a topical gel containing 0.05% PP405 or a placebo, applied once daily for four weeks, with follow-up lasting up to 12 weeks. Results showed that 31% of men with more advanced hair loss who received PP405 experienced a greater than 20% increase in hair density at eight weeks, compared to 0% in the placebo group.
The study also demonstrated that PP405 induced new hair growth in previously bald areas, suggesting a potential regenerative effect. The treatment was also well-tolerated, with no systemic absorption detected in the bloodstream.
William Lowry, professor of molecular biology; Heather Christofk, professor of biological chemistry; and Michael Jung, distinguished professor of chemistry – the three researchers leading the study – expressed optimism about the findings in a conversation with the UCLA news office.
“No product of this type will work for everyone, but our initial human trials have been very encouraging, and larger trials with more participants are on the horizon,” one of the researchers said.
Dr. Pedro Barbosa, a dermatologist specializing in trichology and a member of the Hair Unit at the Austral University Hospital, emphasizes that this molecule has a completely different mechanism of action than those previously studied in androgenetic alopecia. However, he cautions that “the results are promising, but it’s critical to remember that these are clinical trials that still demand proven efficacy.”
Barbosa noted that the eight-week timeframe for observing results in the PP405 study is relatively short for evaluating hair growth. “Any changes in hair will only become apparent after 3-6 months; that’s why we inform patients that patience is key in treatments,” he stated.
If the positive results persist, Barbosa highlights an additional benefit: a topical treatment would be more advantageous than oral medications due to fewer contraindications or side effects.
He also warns that in advanced cases of baldness, no molecule can “awaken” the follicles. “There’s a point where the follicle miniaturizes so much that scarring occurs, making hair recovery impossible,” he explained.
Conversely, he mentions that reversible types of hair loss are “non-scarring” alopecias – those that do not cause scarring on the scalp.
However, he stresses the importance of an accurate diagnosis, periodic photographs, and, above all, patience with the results. “Always proceed to a good dermatologist and, if possible, a specialist in trichology,” he said.
