Oxandrolone and Winstrol Interaction: Avoid | Peptide Database

Join others researching RU-58841 — share findings, ask questions, and learn from real experiences RU-58841 is a non-steroidal anti-androgen originally developed by Roussel Uclaf (later Hoechst Marion Roussel) in the 1970s-80s for topical treatment of androgen-dependent conditions including acne and androgenetic alopecia. It works by competitively binding to androgen receptors at the hair follicle, blocking the effects of dihydrotestosterone (DHT) locally without significantly reducing systemic androgen levels. Development was abandoned after Phase II clinical trials, and the compound was never submitted for regulatory approval. Despite this, RU-58841 has developed a substantial following in the hair loss community, where users source it as a raw research chemical and prepare their own topical solutions. Its extremely short systemic half-life means that even if absorbed through the skin, it is rapidly metabolized, limiting systemic anti-androgenic effects. However, the lack of completed clinical trials means its long-term safety profile remains unknown. RU-58841 functions as a competitive antagonist of the androgen receptor (AR). When applied topically to the scalp, it penetrates the skin and binds directly to androgen receptors in dermal papilla cells of hair follicles, preventing dihydrotestosterone (DHT) and testosterone from activating those receptors. This is fundamentally different from 5-alpha reductase inhibitors like finasteride, which reduce DHT production systemically. RU-58841 does not lower DHT or testosterone levels at all; it simply blocks their action at the receptor level in the tissue where it is applied. The compound has a very high binding affinity for the androgen receptor but an extremely short systemic half-life of roughly one hour due to rapid hydrolysis of its amide bond in the bloodstream. This pharmacokinetic profile is intentional: it confines the anti-androgenic activity to the scalp while minimizing the risk of systemic side effects such as sexual dysfunction or hormonal disruption. Animal studies in hamster flank organ and stumptail macaque models demonstrated significant local anti-androgenic effects, including hair regrowth and inhibition of androgen-dependent sebaceous gland activity, without measurable systemic anti-androgenic effects at therapeutic topical doses.

Used off-label at 0.5mg daily for male pattern hair loss. Clinical trials demonstrate superior efficacy compared to finasteride, with greater increases in target area hair count attributed to dual 5-alpha reductase inhibition and more complete DHT suppression. Strong evidence for regrowth at the vertex region, where DHT-sensitive follicles are most concentrated. The greater DHT suppression achieved by dutasteride may provide additional benefit over finasteride in this area. Effective at slowing frontal hairline recession and improving mid-scalp density. Some evidence suggests dutasteride's dual inhibition provides a modest advantage over finasteride for frontal hair loss, though results vary between individuals. Some men who do not respond adequately to finasteride may benefit from switching to dutasteride, as the additional Type I inhibition provides more complete DHT suppression. Not all finasteride non-responders will respond to dutasteride. FDA-approved at 0.5mg daily for the treatment of symptomatic BPH. Reduces prostate volume by approximately 25% and improves urinary symptoms and flow rate over 6-12 months of treatment. Consistently reduces prostate volume more effectively than finasteride due to dual isoform inhibition, with reductions of 25-30% documented in long-term clinical trials.