WhatsAppBaldness and hair loss, though more common in men but also found in women, are extremely common conditions. Apart from the cosmetic problem, the condition often leads to a loss of self-confidence and psychological issues. The most popular hair loss treatment techniques until now included drugs like Minoxidil and Finasteride, or surgery in the form of hair transplant.
Yet over the past several years, the scientific community has been buzzing about a new promising entrant: PP405. The compound, discovered by three professors at UCLA, functions by reactivating dormant hair follicle stem cells.
While currently still in the experimental treatment phase, early clinical trials are showing PP405 to possibly be one of the most exciting treatments for hair loss and receding hairline. So what do we really know about how this hair loss drug was developed, and what milestones have been reached to this point in time?
PP405’s story started at UCLA in 2013. Professor Bill Lowry, studying skin cancer in mice, noticed something interesting: In active hair follicle stem cells, the enzyme “lactate dehydrogenase” (LDH) was working at extremely high levels.
The enzyme was never associated with hair growth, always with cancer research. Lowry and his collaborator Heather Christofk decided to attempt its function. When they shut off LDH in genetically modified mice, their hair did not regrow. Then, to enhance the activity of LDH, they blocked a protein called “mitochondrial pyruvate carrier” (MPC). The result was dramatic: The mice started to grow new hair quickly.
This study by scientists showed that dormant follicle stem cells can be reactivated. As Lowry described it, the cells were like Batman: Full of potential power but waiting for some signal to spring into action. MPC blockers provided just that. For researchers searching for a new baldness cure, this was a breakthrough.
Animal studies were promising, but there were questions around whether such a therapeutic mechanism could be recognized in humans. Human skin is ten times thicker than the skins of mice, therefore a topical solution needed to effectively penetrate the skin more than it would for a mouse.
When researchers pursed UK-5099 which was a compound which was effective for mice, they learned when it came to hair follicles, the compound could not penetrate human hair follicles. That’s when UCLA chemist Michael Jung, a seasoned researcher who had already developed two FDA-approved cancer treatments, entered the picture.
Jung synthesized dozens of UK-5099 derivatives. The new compounds were tried out on human skin samples excised during cosmetic surgery. The samples survived for only a few days, but scientists noticed that follicle stem cells were activated very rapidly.
In 2018, Lowry, Christofk, and Jung selected the optimal compound, founded Pelage Pharmaceuticals, and named their medication PP405, after Los Angeles’ famous 405 freeway.
For this new hair loss drug, safety was even more important than effectiveness. In 2023, the first human trial was conducted on 16 volunteer men with alopecia. These volunteers, who were experiencing baldness, applied a gel containing PP405 to their scalp every night for a week. Even with daily application, none of the drug was absorbed into the bloodstream, and there were no side effects. This showed that the drug was localized and was a topical agent only.
The experts conducted a phase 2a experimental therapy on some men and women in 2024. One part of the group used PP405 hair regrowth drug, while the other part used a placebo for four weeks. Safety was the top priority, but to their surprise, some patients also experienced improvements in hair density.
In extremely bald men, 31% of them saw more than a 20% increase in hair density after eight weeks. More importantly, the new hairs were not thin “peach fuzz” but thick, terminal hairs.
Compared to Minoxidil—known to many from Minoxidil before and after pictures—which takes months before it takes effect, this was an incredibly fast effect. For men searching Google for “how to regrow thinning hair man” or trying natural remedies like rosemary oil, these results caused much excitement.
Researchers also believe that PP405 can not only help in male pattern baldness but also in other types of hair loss. Although it is in an early phase, it has several positives that are making it so promising:
All these benefits identify PP405 as a highly promising hair regrowth medication. For many patients who have tried medications like Rogaine for men or finasteride with limited success, this compound offers new hope.
| Feature / Drug | Minoxidil | Finasteride | PP405 |
| Mechanism of Action | Indirect effect: Works by promoting blood flow and prolonging the anagen (growth) phase of the hair cycle. | Hormonal blockage: Inhibits dihydrotestosterone (DHT) to protect hair follicles. | Works at the cellular metabolism level. Does not interfere with hormones. |
| Application Method | Topical (applied to scalp as liquid or foam). | Oral (taken as pill). | Topical solution (does not require injections). |
| Goal | Firstly slows hair thinning and partially supports hair regrowth. | Slows hair loss, protects existing hair. | Not aimed at slowing hair loss, but at regrowing terminal hair by reactivating dormant follicles. |
| FDA Approval | FDA approved. | FDA approved. | In trial phase; not FDA approved. |
| Key Point | Mainly slows male and female pattern baldness; partly stimulates new hair growth. | Effective in male pattern baldness due to hormonal pathway. | Novel approach: Works directly at cellular level without hormonal interference; goal is true regrowth. |
Despite the optimism, scientists are cautious. They point out that while early effects are promising, it is unclear whether they will endure. Many drugs that have looked good in the early stages of trials have subsequently failed.
Pelage Pharmaceuticals anticipates starting Phase 3 trials for Norwood hair loss levels in 2026. Assuming no delays, PP405 could be available on the market within a few years’ time. The company has already created a lot of investor excitement, with more than $30 million having been raised. For those experiencing hair loss today, though, even three years may be a very long time.
This medication, which is at an experimental level, may be used by experts in the following ways in the future:
This might potentially have synergistic effects with one another. This might be a major advance, but more scientific data needs to be obtained, including high-quality before and after imaging.
Although PP405 hair cure drug appears to be a promising new treatment, it is still in the process of being developed. For now, there are just two FDA-approved medications for hair loss available: Minoxidil and Finasteride. And for those who prefer the most tried-and-true method, hair replacement surgery remains the gold standard.
Dr. Resul Yaman Hair Clinic understands the advances in science but recognizes that, as of now, hair transplant surgery is still the most effective, safest, and permanent solution for baldness. While there is potential for breakthrough treatments like PP405 to change the future for hair loss, hair plantations leave patients in the most tangible position of achieving a more natural as well as long lasting outcome.
The search for a new baldness treatment is ongoing at a furious pace, and everyone wants to know whether this hair regrowth medication will deliver on what early research promises. If future research keeps yielding positive results, PP405 could very well be the breakthrough hair loss medication sooner rather than later.
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