Overview
RU58841, also known by the research designations PSK-3841 or HMR-3841, is a non-steroidal anti-androgen (NSAA) specifically investigated for its potential to treat androgenetic alopecia. Originally developed in the 1990s by Roussel Uclaf, the compound was initially explored for prostate cancer treatment before researchers pivoted to its hair-regrowth properties. Unlike systemic treatments like finasteride, which inhibit the 5-alpha reductase enzyme to lower overall DHT levels, RU58841 functions as a topical receptor antagonist.
This localized approach is designed to prevent follicle miniaturization while sparing the rest of the body from the hormonal fluctuations often associated with hair loss medications. Although it reached Phase II clinical trials under the company Prostrakan, it never received FDA approval for human use and remains classified as a research chemical. It is most commonly found in liquid solutions or raw powder forms for topical application, aimed at restoring the natural hair growth cycle in those suffering from male pattern baldness.
Mechanism of action
RU58841 is a non-steroidal anti-androgen that competes with dihydrotestosterone (DHT) for binding sites on androgen receptors within hair follicles. By blocking these receptors locally, it prevents DHT from miniaturizing follicles without lowering systemic androgen levels.
Reported benefits
- ▸Counteracts androgenetic alopecia by blocking DHT receptors on the scalp.
- ▸Promotes the transition of hair follicles into the active growth (anagen) phase.
- ▸Preserves systemic testosterone and DHT levels unlike oral anti-androgens.
- ▸Strengthens existing hair and supports the recovery of damaged follicles.
- ▸Localizes treatment to the scalp to minimize impact on muscle mass and libido.
Reported side effects
- ·Potential for localized skin irritation
- ·Scalp redness or itching
- ·Rare systemic anti-androgen effects if absorbed excessively
- ·Long-term safety remains unconfirmed in humans
Often stacked with
MinoxidilKetoconazole shampooMicroneedling therapy