PP405 is a topical compound that targets follicle metabolism rather than hormones. It came out of UCLA, completed a Phase 1 study in January 2024 and a Phase 2a trial in 78 adults (NCT06393452), and its sponsor has said Phase 3 was planned for 2026. It is investigational and not FDA-approved.
The short version
- PP405 is described by its sponsor as a topical mitochondrial pyruvate carrier (MPC) inhibitor that upregulates lactate dehydrogenase in hair follicle stem cells.
- It was developed from UCLA research by William Lowry, Heather Christofk and Michael Jung; the intellectual property was licensed in 2018.
- Phase 1 completed January 2024: seven days of topical dosing, no detectable drug levels in blood.
- Phase 2a enrolled 78 men and women, dosed daily for four weeks and followed to twelve weeks. The primary endpoint was safety, and it was met.
- The headline density figure came from an exploratory endpoint, not the primary one.
What is the mechanism, in plain terms?
Hair follicle stem cells sit dormant for long stretches. The UCLA work behind PP405 concerns how those cells use fuel: blocking the mitochondrial pyruvate carrier shifts cells toward producing lactate, and the sponsor reports that shift is associated with activating the stem cells. This is a metabolic route, which is what makes it different in kind from the hormonal and vascular approaches that dominate the field.
Two caveats belong right next to that. A mechanism being plausible is not the same as a clinical result, and this mechanism has so far been tested in humans for weeks rather than months.
How did the PP405 studies progress?
| Stage | Subjects | Dosing | What was reported |
|---|---|---|---|
| Ex vivo (AAD 2024) | Human facelift skin | 0.006% and 0.06%, single application | Increased LDH activity and Ki67 in the hair bulge at 24 hours |
| Phase 1 (completed Jan 2024) | Not disclosed | 0.05% topical, seven days | Safety and pharmacokinetics; no detectable blood levels; Ki67 rose from baseline |
| Phase 2a (NCT06393452) | 78 adults | Daily for four weeks, followed to twelve weeks | Primary endpoint safety, met; no systemic absorption detected |
What did the Phase 2a trial actually find?
The trial was designed around safety, and Pelage reported that the primary endpoint was met with no systemic absorption detected. The finding that drew coverage was an exploratory one: at week eight, 31% of men receiving PP405 who had more advanced hair loss showed a greater than 20% increase in hair density, against none in the placebo group. The company described these as preliminary results from one month of application.
The distinction between a primary and an exploratory endpoint matters more than it sounds. A primary endpoint is declared in advance and the trial is sized to test it. Exploratory endpoints are looked at afterwards, on smaller subgroups, and are read as hypothesis-generating. The 31% figure describes a subgroup of one arm of a 78-person safety study.
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What these results do not tell you
- The trial was powered for safety. Efficacy signals from a safety trial are hypothesis-generating, not conclusions.
- 31% is a subgroup figure. It describes men with more advanced loss inside a 78-person study, not everyone who used it.
- Four weeks of dosing. Hair cycles run in months. Twelve weeks of follow-up cannot describe durability.
- No published paper is cited here. The figures come from the sponsor's announcements and conference presentations.
- Phase 3 is planned, not reported. A planned trial is not a result.
Where does 2-deoxy-D-ribose sit against this?
Further back, and in a different regulatory category. 2-deoxy-D-ribose (2DDR) is a naturally occurring pentose sugar. The work most often cited is a 2024 paper in Frontiers in Pharmacology from the University of Sheffield and COMSATS University, which applied it in a testosterone-driven mouse model and reported hair growth outcomes in that model similar to the minoxidil comparator used in the same study. That is an animal study, and the lead author described the work publicly as early stage.
One independent randomised controlled trial of a 2-deoxy-D-ribose hydrogel (NCT07502976) began recruiting in January 2026 at Kasr El Aini Hospital, with 60 participants estimated and primary completion listed for October 2026. No results have been posted. That trial is run by an academic hospital and is not a study of any commercial product.
So the honest summary is: an animal model, a mechanistic hypothesis about blood vessel formation, and one human trial that has not reported. Set against a completed Phase 3 programme, that is not a close comparison, and this article does not make one.
Deoxylocks is a physician-formulated cosmetic hydrogel containing 5% 2-deoxy-D-ribose. It is a scalp care product sold for cosmetic use. It is not a drug, it has not been through the trials described in this article, and nothing here was conducted on it. Anyone weighing the options in this article should speak with a clinician about their own situation.
Common questions
Can I get PP405?
No. It is investigational and not approved. Access outside a registered clinical trial is not available.
Is PP405 a stem cell product?
Not in the sense of transplanting cells. It is a small molecule applied to the scalp that the sponsor reports acts on the metabolism of stem cells already present.
Why is a safety trial getting so much coverage?
Because the exploratory density figure was striking and the mechanism is novel. Both are reasons to pay attention and reasons to wait for a trial designed to measure it.
Where can I read the trial record?
The Phase 2a study is NCT06393452, linked below along with the sponsor announcements.
Last checked 15 August 2026.
Sources
Primary sources for the figures in this article. Registry records were checked on 15 August 2026.
- PP405 Phase 2a (NCT06393452)
- Pelage Phase 2a results announcement
- Pelage AAD 2024 Phase 1 and ex vivo data
- Stimulation of hair regrowth in an animal model of androgenic alopecia using 2-deoxy-D-ribose
- University of Sheffield announcement
- 2-Deoxy-D-ribose hydrogel vs minoxidil 5% (NCT07502976)
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These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
