RU58841
updated
RU58841, later called PSK3841, is a topical antiandrogen research chemical. Animal and human-scalp-graft models are positive, but the two completed human study registrations have no posted results, so efficacy and systemic safety in people remain unresolved.
nonsteroidal androgen-receptor antagonist
- Small molecule, not a peptide
- Androgen-receptor antagonist
- Preclinical macaque and human-scalp-graft data
- Completed human registrations without public results
What exactly is RU58841?
RU58841 is a synthetic nonsteroidal androgen-receptor antagonist and small molecule, not a peptide. PSK3841 is the later development code used in its human trial registrations.
Macaque study · follicular antiandrogen signal
Animal study
Uno H et al. Journal of Steroid Biochemistry and Molecular Biology, 1998.
Topical RU58841 produced hair-growth and follicular changes in a balding stumptailed-macaque model. The study also included receptor and tissue assays. It did not test clinical hair outcomes or systemic safety in people.
- Participants / model
- Stumptailed macaques with a balding phenotype plus laboratory assays
- Treatment
- Topical RU58841
- Study design
- Controlled animal and pharmacology study
ISRCTN49873657 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind study of 5% topical PSK3841 over four weeks in men with androgenetic alopecia. The record does not provide a results report.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- 5% topical PSK3841
- Follow-up
- 4 weeks
- Study design
- Registered randomized double-blind safety and tolerance study
Completed status is sponsor-reported and is not a published result.
Read the original sourceDoes RU58841 grow hair in people?
The registry records do not provide a usable efficacy result. Both studies are marked completed, but neither posts results or cites a peer-reviewed outcome paper.
The registrations describe what researchers planned to measure, but provide no hair-growth results or adverse-event counts.
ISRCTN49873657 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind study of 5% topical PSK3841 over four weeks in men with androgenetic alopecia. The record does not provide a results report.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- 5% topical PSK3841
- Follow-up
- 4 weeks
- Study design
- Registered randomized double-blind safety and tolerance study
Completed status is sponsor-reported and is not a published result.
Read the original sourceISRCTN71083772 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind six-month study of topical 2.5% and 5% PSK3841 in men with androgenetic alopecia. It posts no results; the cited records include no peer-reviewed outcome publication.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- Topical 2.5% or 5% PSK3841 and controls
- Follow-up
- 6 months
- Study design
- Registered randomized double-blind efficacy study
The registration establishes that a study was planned and reported completed, not what it found.
Read the original sourceWhat do the positive studies actually test?
Topical RU58841 produced signals in balding macaques and in human scalp grafted onto mice. Those models support local androgen-receptor biology, but they cannot establish human efficacy, absorption, endocrine effects, or long-term safety.
Macaque study · follicular antiandrogen signal
Animal study
Uno H et al. Journal of Steroid Biochemistry and Molecular Biology, 1998.
Topical RU58841 produced hair-growth and follicular changes in a balding stumptailed-macaque model. The study also included receptor and tissue assays. It did not test clinical hair outcomes or systemic safety in people.
- Participants / model
- Stumptailed macaques with a balding phenotype plus laboratory assays
- Treatment
- Topical RU58841
- Study design
- Controlled animal and pharmacology study
Scalp graft · human tissue on mice
Xenograft animal study
Brouwer B et al. Journal of Steroid Biochemistry and Molecular Biology, 1997.
Researchers treated balding human scalp tissue after grafting it onto nude mice and observed follicular effects with topical RU58841. The biological tissue was human, but the treated subjects were mice, not patients.
- Participants / model
- Human scalp xenografts maintained on nude mice
- Treatment
- Topical 1% RU58841 in the xenograft model
- Study design
- Animal xenograft experiment
The scalp tissue was human; treatment was tested on mice.
Read the original sourceHow does this compare with established hair-loss options?
RU58841 lacks public human outcome data and an approved product label. Topical minoxidil and oral finasteride have regulated products and clinical datasets, so their benefits and risks can be assessed from evidence that RU58841 does not publicly provide.
ISRCTN71083772 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind six-month study of topical 2.5% and 5% PSK3841 in men with androgenetic alopecia. It posts no results; the cited records include no peer-reviewed outcome publication.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- Topical 2.5% or 5% PSK3841 and controls
- Follow-up
- 6 months
- Study design
- Registered randomized double-blind efficacy study
The registration establishes that a study was planned and reported completed, not what it found.
Read the original sourceDrugs@FDA/openFDA · no approval record found
US approval status
Drugs@FDA and openFDA.
No US approved-drug record matches RU58841 or PSK3841.
Read the original sourceWhat is known about systemic risk?
The unpublished registrations do not provide adverse-event counts or pharmacokinetics. Absorption, sexual or reproductive effects, fetal risk, cardiovascular effects, interactions, and long-term local irritation remain unresolved, along with purity and concentration in research-chemical products.
ISRCTN49873657 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind study of 5% topical PSK3841 over four weeks in men with androgenetic alopecia. The record does not provide a results report.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- 5% topical PSK3841
- Follow-up
- 4 weeks
- Study design
- Registered randomized double-blind safety and tolerance study
Completed status is sponsor-reported and is not a published result.
Read the original sourceISRCTN71083772 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind six-month study of topical 2.5% and 5% PSK3841 in men with androgenetic alopecia. It posts no results; the cited records include no peer-reviewed outcome publication.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- Topical 2.5% or 5% PSK3841 and controls
- Follow-up
- 6 months
- Study design
- Registered randomized double-blind efficacy study
The registration establishes that a study was planned and reported completed, not what it found.
Read the original sourceDrugs@FDA/openFDA · no approval record found
US approval status
Drugs@FDA and openFDA.
No US approved-drug record matches RU58841 or PSK3841.
Read the original sourceIs RU58841 FDA approved?
No US approved-drug record appears for RU58841 or PSK3841 in Drugs@FDA or openFDA. This conclusion is limited to US approval records.
Drugs@FDA/openFDA · no approval record found
US approval status
Drugs@FDA and openFDA.
No US approved-drug record matches RU58841 or PSK3841.
Read the original sourceStudies and sources
Macaque study · follicular antiandrogen signal
Animal study
Uno H et al. Journal of Steroid Biochemistry and Molecular Biology, 1998.
Topical RU58841 produced hair-growth and follicular changes in a balding stumptailed-macaque model. The study also included receptor and tissue assays. It did not test clinical hair outcomes or systemic safety in people.
- Participants / model
- Stumptailed macaques with a balding phenotype plus laboratory assays
- Treatment
- Topical RU58841
- Study design
- Controlled animal and pharmacology study
Scalp graft · human tissue on mice
Xenograft animal study
Brouwer B et al. Journal of Steroid Biochemistry and Molecular Biology, 1997.
Researchers treated balding human scalp tissue after grafting it onto nude mice and observed follicular effects with topical RU58841. The biological tissue was human, but the treated subjects were mice, not patients.
- Participants / model
- Human scalp xenografts maintained on nude mice
- Treatment
- Topical 1% RU58841 in the xenograft model
- Study design
- Animal xenograft experiment
The scalp tissue was human; treatment was tested on mice.
Read the original sourceISRCTN49873657 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind study of 5% topical PSK3841 over four weeks in men with androgenetic alopecia. The record does not provide a results report.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- 5% topical PSK3841
- Follow-up
- 4 weeks
- Study design
- Registered randomized double-blind safety and tolerance study
Completed status is sponsor-reported and is not a published result.
Read the original sourceISRCTN71083772 · completed, no results
Trial registry record
ISRCTN registry.
The registry describes a completed randomized double-blind six-month study of topical 2.5% and 5% PSK3841 in men with androgenetic alopecia. It posts no results; the cited records include no peer-reviewed outcome publication.
- Participants / model
- Men with androgenetic alopecia
- Treatment
- Topical 2.5% or 5% PSK3841 and controls
- Follow-up
- 6 months
- Study design
- Registered randomized double-blind efficacy study
The registration establishes that a study was planned and reported completed, not what it found.
Read the original sourceDrugs@FDA/openFDA · no approval record found
US approval status
Drugs@FDA and openFDA.
No US approved-drug record matches RU58841 or PSK3841.
Read the original sourceWhy is RU58841 in C tier?
C tier reflects animal and human-scalp-graft findings. The completed human trials have no public results establishing hair growth or safety.