RU-58841
RU58841 / PSK-3841 (topical antiandrogen) · Topical androgen receptor blocker (unapproved)
What it is
An abandoned 1990s French pharmaceutical candidate — a topical antiandrogen designed to block DHT at the hair follicle without (in theory) finasteride's systemic suppression. Development died in corporate transitions; it survives only as an unapproved product.
What human evidence shows
Animal studies (notably the macaque hair-growth work) plus early human safety trials from the original program. It never completed efficacy trials in people — the large online testimonial base is uncontrolled self-experimentation on a compound with no finished dossier.
Risks
Long-term human safety, systemic exposure, and product stability are not established. Its metabolite is a potent antiandrogen, and the systemic effects of chronic scalp application were never characterized; anecdotal reports of libido or mood changes exist but are not established effects. No approved formulation means no concentration or purity standard.
Legal status
US: not FDA-approved for any use.
Evidence base
early literature
Studied, but no human trial report found. A real literature that is preclinical as far as these counts can see.
- phase 3/4
- 0
- randomised
- 0
- reviews
- 0
- human trials
- 0
Counts are of published papers, not distinct trials, and measure how much research exists — not whether this works or is safe for you.
Research (11)
- RU 58841, a new specific topical antiandrogen: a candidate of choice for the treatment of acne, androgenetic alopecia and hirsutismJ Steroid Biochem Mol Biol · 1994
- Local inhibition of sebaceous gland growth by topically applied RU 58841Ann N Y Acad Sci · 1995
- RU 58841-myristate--prodrug development for topical treatment of acne and androgenetic alopeciaPharmazie · 2005
- Preliminary pharmacokinetics and metabolism of novel non-steroidal antiandrogens in the rat: relation of their systemic activity to the formation of a common metaboliteJ Steroid Biochem Mol Biol · 1994
- Synthesis and structure-activity studies of side-chain derivatized arylhydantoins for investigation as androgen receptor radioligandsBioorg Med Chem Lett · 2001
- Importance of sebaceous glands in cutaneous penetration of an antiandrogen: target effect of liposomesJ Pharm Sci · 1997
- Inhibition of hair growth by testosterone in the presence of dermal papilla cells from the frontal bald scalp of the postpubertal stumptailed macaqueEndocrinology · 1997
- Cyproterone acetate loading to lipid nanoparticles for topical acne treatment: particle characterisation and skin uptakePharm Res · 2007
- Promotion of agonist activity of antiandrogens by the androgen receptor coactivator, ARA70, in human prostate cancer DU145 cellsProc Natl Acad Sci U S A · 1998
- Evaluation of RU58841 as an anti-androgen in prostate PC3 cells and a topical anti-alopecia agent in the bald scalp of stumptailed macaquesEndocrine · 1998
- A controlled study of the effects of RU58841, a non-steroidal antiandrogen, on human hair production by balding scalp grafts maintained on testosterone-conditioned nude miceBr J Dermatol · 1997
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