RU58841

RU58841 is a topical nonsteroidal androgen-receptor antagonist research chemical with macaque and human-scalp-graft signals, plus two completed human-study registrations without published results.

tier C · skin · 0 located published human outcome reports

verdict

Topical RU58841 produced hair signals in a stumptailed-macaque model and in human scalp grafts carried by nude mice. Those preclinical results cannot answer how well it works, how it is absorbed, or how safe it is on a person's scalp.

the core tension

The androgen-receptor mechanism and preclinical hair signal are plausible. The human program is visible only as registrations without results, leaving efficacy, systemic exposure, adverse events, and product quality unresolved.

what it is

RU58841, also registered as PSK3841, is a synthetic nonsteroidal small-molecule androgen-receptor antagonist. It is not a peptide.

what it does

Cell work showed competitive androgen-receptor antagonism. Topical preclinical models reported hair-cycle or hair-growth signals under androgen pressure.

origin

Published preclinical papers appeared in 1997 and 1998. Later PSK3841 human studies were registered as completed, but the reviewed registry records do not provide results.

does it work

Human efficacy is unknown. The human scalp tissue in one paper was grafted onto nude mice, and the two registered human studies cannot be treated as positive without reported data.

key facts

• molecular formula: C17H18F3N3O3
• molecular weight: 369.34 g/mol
• amino acids: n/a (nonsteroidal small molecule, not a peptide)
• half-life: unknown; no located published human PK result
• type: nonsteroidal androgen-receptor antagonist research chemical
• CAS: 154992-24-2
• 2 completed human-study registrations without located results
• 0 located published human efficacy reports
• 1% topical concentration in the nude-mouse scalp-graft paper

frequently asked questions

Has RU58841 been studied in people?

Two PSK3841 human studies are registered as completed. Their reviewed registry records do not post results, so they do not establish human efficacy, PK, or safety.

Did the scalp-graft study treat people?

No. Human scalp grafts were maintained on testosterone-conditioned nude mice and treated topically there.

Does the macaque study prove hair regrowth in humans?

No. It is a nonhuman-primate alopecia model and remains preclinical evidence.

What is the human half-life?

Unknown. No located published human PK result reports a defensible half-life.

Is RU58841 FDA approved?

No FDA-approved RU58841 application was located in the exact-name Drugs@FDA query checked on August 15, 2026.

related peptides

• Finasteride: compare with RU58841's missing published human outcome record
• Minoxidil: compare without promoting the nude-mouse scalp-graft result to human evidence

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.