Finasteride Vs PP405: How They Compare For Hair Loss
Last reviewed on 12 October 2026. We review our treatment guides every six months to keep them accurate.
Key points
They work in completely different ways. Finasteride lowers the hormone that drives male pattern hair loss, while PP405 is an experimental topical that tries to wake dormant follicles back up.
Finasteride is the proven, first-line option. Taken as a daily tablet, it blocks the enzyme that makes DHT, cutting the hormone by around 70 per cent and protecting follicles from being shrunk. It is licensed for hair loss and backed by long-standing evidence.
PP405 is promising but unproven. It is a topical designed to switch tired follicle stem cells back on by changing how they use energy, a newer, more regenerative idea, but it is still in clinical trials and not approved.
The decisive difference is availability and evidence. Finasteride is available now with strong evidence; PP405 is not yet available, and for it the fullest results have not been published in peer-reviewed journals.
Because they do different jobs, they are not really rivals. One lowers the hormone and the other wakes the stem cells, so in principle they could complement each other rather than compete.
PP405’s appeal is being non-hormonal. Some people want to avoid a hormonal tablet, which is part of why an experimental topical that works a different way has drawn so much interest, but it cannot yet be chosen.
Neither can bring back hair that is truly gone. Finasteride protects the hair you have and PP405 aims to revive dormant follicles; where follicles are lost, a hair transplant is the only option that adds hair. Which suits you is best decided with a clinician.
Finasteride and PP405 are often set against each other because they represent two very different directions for treating hair loss: one a proven drug that tackles the hormone behind male pattern loss, the other an experimental topical that tries to reactivate dormant follicles. Finasteride is a daily tablet that lowers DHT and is a first-line, licensed treatment. PP405 is a newer idea still in clinical trials. The key differences are how they work, and how proven and available each is.
This guide compares finasteride and PP405 neutrally: what each is, how they differ, how effective they are, where each stands, who each suits, and how they fit with other treatments. It is general information and not a substitute for advice from a doctor.
The short answer
Finasteride and PP405 approach hair loss in opposite ways, and they are at very different stages. Finasteride is a proven, first-line tablet: it blocks the enzyme that makes DHT, the hormone that drives male pattern loss, cutting it by around 70 per cent and protecting follicles from being shrunk. It is licensed for hair loss, cheap, and backed by long-standing evidence, though it is a hormonal drug that some people would rather avoid. PP405 is a different kind of treatment altogether: an experimental topical designed to wake dormant follicle stem cells by changing how they use energy, a more regenerative idea aimed at reviving tired follicles rather than protecting them from a hormone. It is promising, but still in trials, not approved, and its fullest results have not yet been published in peer-reviewed journals. So, in practice, finasteride is the proven option you can use now, while PP405 is a non-hormonal topical to watch for the future. Because one lowers the hormone and the other wakes the stem cells, they are not really competitors, and could in principle be used together. Neither, in any case, can bring back follicles that are already gone.
What is finasteride?
Finasteride is a daily tablet that treats male pattern hair loss by lowering DHT, the hormone that shrinks genetically sensitive follicles. As a 2023 review of 5-alpha-reductase inhibitors explains, the enzyme it blocks "converts testosterone to dihydrotestosterone (DHT), which amplifies androgen effects in certain tissues", and finasteride produces "a substantial reduction in serum (around 70%)" DHT. By cutting the hormone, it protects the follicles and slows, halts or partly reverses the loss. It is the standard first-line medical treatment, it is licensed for hair loss in men, and its evidence is strong and long-standing: the same review notes that "long-term use of finasteride at a 1-mg dose proved to be safe and effective in treating male-pattern" hair loss. It is a hormonal drug taken by mouth, which is why a minority of men are concerned about side effects. Our guide on finasteride for hair loss covers it in detail, including the possible side effects, and finasteride versus minoxidil compares it with the other mainstay.
What is PP405?
PP405 is an experimental topical from the company Pelage, aimed not at hormones but at the follicle’s own stem cells. It grew out of research at UCLA into how hair-follicle stem cells use energy. That work, published in Nature Cell Biology, found that "HFSCs utilize glycolytic metabolism and produce significantly more lactate than other cells in the epidermis", and that pushing cells to make more lactate wakes them up: "loss of function of Mpc1 has been shown to drive lactate production through enhanced conversion of pyruvate to lactate by Ldh", and in animals, deleting that carrier produced "a strong acceleration of the ventral and dorsal hair cycles". The researchers showed a topical small molecule could do the same: "topical treatment of animals in telogen (day 50) with UK-5099 led to a robust acceleration of the hair cycle". PP405 is the drug built on this idea, designed to switch dormant follicles back on. It is applied to the scalp and has been through early human trials, but, as our guide on PP405 for hair loss explains, its results so far come mainly from company announcements rather than full peer-reviewed publications, and it is not yet approved.
Which is more effective for hair loss?
On the evidence available, finasteride is clearly the more proven treatment, simply because it is established and PP405 is not. Finasteride has decades of use and strong trial support for holding on to and partly regrowing hair, as the 5-ARI review sets out, and it is licensed for the purpose. PP405 is based on solid laboratory science, shown in the UCLA work above, and the company has reported encouraging early trial results, but those results have not yet been published in full in peer-reviewed journals, and larger, longer trials are still to come.
The two are also not directly comparable, because they do different jobs. Finasteride protects follicles from the hormone that shrinks them, with proven results; PP405 tries to revive follicles that have gone dormant, with a plausible mechanism but, as yet, no published, independent human evidence to show how well it works. So the honest position is that finasteride is the proven, available option, while PP405 is a promising but unproven one that tackles a different part of the problem.
Finasteride vs PP405: how do they compare?
They differ in almost every respect: mechanism, form, evidence and availability.
What they are: finasteride is an oral prescription tablet; PP405 is an experimental topical gel.
How they work: finasteride lowers DHT production, protecting follicles from the hormone that shrinks them; PP405 changes how follicle stem cells use energy to wake dormant follicles, a more regenerative approach.
What they tackle: finasteride defends follicles against the hormonal cause; PP405 tries to revive follicles that have gone dormant. One defends, the other revives.
Availability: finasteride is licensed and available for hair loss now; PP405 is still in clinical trials and not approved.
Evidence: finasteride has strong, long-standing evidence; PP405 is promising but early, with the fullest trial results not yet published in peer-reviewed journals.
Hormonal or not: finasteride is a hormonal drug taken by mouth, which a minority find off-putting because of possible side effects; PP405 is non-hormonal and applied to the scalp, which is part of its appeal.
Rivals or partners: because one lowers the hormone and the other wakes the stem cells, they are complementary rather than competing, and could in principle be used together.
What neither does: neither can bring back follicles that are already gone, so both are for protecting or reviving follicles that are still there rather than replacing hair that is lost.
Which is right for you?
In practical terms today, finasteride is the option you can actually use: it is proven, licensed, inexpensive and works on the cause by lowering DHT, which is why it is the standard first-line medical treatment. The main reason some people look elsewhere is that it is a hormonal drug taken by mouth, and a minority are concerned about side effects, which is exactly the gap a non-hormonal treatment like PP405 might one day fill. But PP405 is not yet available, so however appealing the idea of reactivating dormant follicles without touching hormones, it is not a choice you can make right now, and it remains promising rather than proven. The more useful way to think about them is as two different approaches: finasteride to protect hair from DHT, proven and available; PP405 to wake dormant follicles, experimental and one to watch, with the possibility that, in time, the two could even be combined.
Neither, in any case, suits someone whose follicles are already gone, because both aim to protect or revive follicles that are still there, not to create new ones. Because finasteride is a prescription medicine and PP405 is still experimental, the sensible step is to discuss your options with a clinician, who can weigh up your pattern of loss and your feelings about a hormonal drug, and keep you informed as newer treatments reach approval.
Can they be combined with other treatments?
For now, combining finasteride and PP405 is theoretical, because PP405 is not yet available. In principle it is an appealing pairing, because finasteride would lower the hormone while PP405 would wake dormant follicles, so the two attack the problem at different points and should not overlap. In practice today, finasteride is most often combined with minoxidil, a topical that stimulates the follicles by yet another route, which we compare in our guide on finasteride versus minoxidil. The other emerging comparisons, including the anti-androgen clascoterone and PP405 itself, are covered in our guides on finasteride versus Breezula and Breezula versus PP405.
Neither finasteride nor PP405 can restore hair where the follicles have been lost. Where loss is advanced, a hair transplant is a separate option that redistributes your own permanent hair, and a DHT-lowering drug like finasteride is often used around a transplant to protect and support the result; our guide on hair transplant versus finasteride looks at how the two fit together. The key point is that these are treatments to protect or support the hair you have, used as part of a wider plan, not a cure.
The bottom line
Finasteride and PP405 tackle hair loss in opposite ways. Finasteride is a proven, first-line tablet that lowers DHT, the hormone behind male pattern hair loss, protecting follicles from being shrunk; it is licensed, cheap and backed by long-standing evidence, though it is a hormonal drug some prefer to avoid. PP405 is an experimental topical that tries to reactivate dormant follicles by changing how their stem cells use energy, a more regenerative approach, but it is still in trials, not approved, and its fullest results have not yet been published in peer-reviewed journals. Neither can bring back follicles that are already gone.
If you are choosing a treatment today, finasteride is the proven, available option, while PP405 is a non-hormonal topical to watch for the future. The two are not really rivals: finasteride protects hair from DHT, and PP405 would wake dormant follicles, so they may one day be used together. A clinician can help you decide what suits your hair loss now, including how you feel about a hormonal drug, and how newer treatments might fit in once they are approved.
Frequently asked questions
Is PP405 better than finasteride for hair loss?
On the evidence available, no, because finasteride is proven and PP405 is not. Finasteride is a licensed, first-line treatment with long-standing evidence that it lowers DHT and protects follicles. PP405 is an experimental topical with a promising, more regenerative mechanism, but its fullest results have not yet been published in peer-reviewed journals and it is not approved. PP405’s appeal is being non-hormonal, which may suit people who want to avoid a hormonal tablet, but that is a reason to watch it, not evidence that it works better. For now, finasteride remains the proven choice.
Is PP405 available yet?
No. PP405 is still in clinical trials and has not been approved for hair loss. The company has reported encouraging early results, but the full data has not yet been published in peer-reviewed journals, and no approval has been granted, so it cannot yet be bought or prescribed. Finasteride, by contrast, is licensed for male pattern hair loss and available now on prescription.
What is the difference between finasteride and PP405?
They tackle hair loss in opposite ways. Finasteride is an oral tablet that lowers DHT, the hormone that shrinks follicles, protecting the hair you have; it is proven and licensed. PP405 is an experimental topical that tries to wake dormant follicle stem cells by changing how they use energy, aiming to revive tired follicles rather than protect them from a hormone. So finasteride defends against the hormonal cause, while PP405 tries to revive dormant follicles; and finasteride is available now, while PP405 is still in development.
Would PP405 avoid finasteride’s side effects?
That is part of the hope, but it is not yet established. Finasteride is a hormonal drug taken by mouth, and a minority of men are concerned about sexual or mood-related side effects. PP405 is non-hormonal and applied to the scalp, so in principle it would not carry the same hormonal risks, which is a large part of its appeal. However, PP405 is still in trials, and its own long-term safety in people has not yet been established in full, peer-reviewed data. So while it may avoid finasteride’s particular concerns, that cannot yet be taken as proven.
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