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PP405, what it is and where it stands in development
The name PP405 appears more and more often in articles and posts about hair. This text explains what PP405 is, who is developing it and what stage it is at, because a fair amount of inaccurate claims have built up around it.
What PP405 is
PP405 is the designation of an experimental molecule being developed by the American pharmaceutical company Pelage Pharmaceuticals. It grew out of research at the University of California, Los Angeles into the metabolism of hair follicle stem cells.
Put simply, the research started from the observation that stem cells in a dormant follicle behave differently at the level of cell metabolism than those in an active follicle, and looked at whether that metabolism can be influenced.
Three things to know
PP405 is not a peptide. It is a small molecule compound, chemically a completely different kind of substance from the peptides used in cosmetics. The name sounds similar to peptide designations, and that is probably one reason for the confusion, but structurally they have nothing in common.
PP405 is not an approved medicine. It is in clinical trials. That means its safety and efficacy are still being tested and that it is not registered in any country for use in patients.
PP405 is not available. It cannot be bought, with or without a prescription. Any product claiming to contain PP405 or to be equivalent to PP405 is making a claim that cannot be verified.
What the phases of clinical trials mean
Since PP405 is most often mentioned together with a phase, it helps to know what those phases mean.
- Preclinical phase, studies in the laboratory and in animals, before any use in humans.
- Phase 1, a small number of participants, the aim is above all safety and tolerability.
- Phase 2, a larger number of participants, testing whether there is an effect and at what dose.
- Phase 3, a large number of participants, comparison with existing treatment or placebo. This is the phase that precedes the application for registration.
- Registration, the regulator assesses the data and decides on approval.
The road from the first phase to the pharmacy takes years and a large number of molecules never make it. That is not a failure but a usual outcome: most candidates drop out along the way.
Why it is mentioned alongside cosmetics
Public interest in PP405 has been used in marketing, so its name appears on the packaging of cosmetic products too, usually with wording such as “inspired by”.
It is worth being clear: a cosmetic product does not contain PP405 and cannot have its effect. Cosmetics and a medicine in clinical trials are two separate categories, with different regulations, different testing and different claims they are allowed to make.
If you see the name of a molecule that is in clinical trials on a product, that is a marketing reference, not information about the composition. Composition is read from the INCI list.
How to follow the development
Data on clinical trials is public. Registries such as ClinicalTrials.gov publish the status of a trial, the number of participants and the outcomes. That is a more reliable source than social media posts.
Be wary of texts announcing a market launch date. Such announcements are almost always guesswork, because the date depends on the outcome of the trials and the regulator’s decision.
What to do in the meantime
For those dealing with thinning hair now, there are registered preparations that a doctor decides on. We wrote about one of them in the text Minoxidil.
Before any decision it makes sense to establish what kind of condition it is, because different forms of hair loss are dealt with in completely different ways. We gave an overview in the text Alopecia.
Scalp care and cosmetic products are a separate category with their own, more modest scope, covered in the text Hair serums and ampoules.
In short
PP405 is an experimental molecule in clinical trials, it is not a peptide, it is not approved and it is not available. It is worth following through the official clinical trial registries. It is not worth looking for it in cosmetic products, because it is not there.