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Amber glass dropper vial of RU58841 topical solution, 2000 mg concentration, labeled Batch No.005 with expiration date 02-09-2025, set against a clean beige background with slight spacing around the vial
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Ru58841 2000mg topical vial

Ru58841 2000mg topical vial

€45,00 EUR
Taxes included.

                                            NOT FOR HUMAN CONSUMPTION

RU58841 is a topical, non-steroidal androgen-receptor (AR) antagonist investigated for androgenetic alopecia (AGA). It competitively blocks DHT/testosterone at the follicular AR without inhibiting 5-α-reductase or lowering systemic androgens, aiming for local antiandrogen activity with minimal systemic exposure. It is not approved by any major regulator; most human data come from small early-phase studies and patents. It’s commonly sold online as a research chemical of variable quality.

Additional Benefits of RU58841 Now Under Investigation

Benefit Key take-aways
1 Scalp-localized AR blockade Designed to antagonize AR within hair follicles, reducing miniaturization drivers while preserving serum DHT/Testosterone, unlike oral 5-AR inhibitors.
2 Hair-count/diameter signals Early clinical and preclinical work reported increased terminal-hair counts and shaft thickeningversus vehicle in male-pattern hair loss; magnitude appears modest to moderate and dose-dependent.
3 Rapid onset vs systemic options Some datasets show visible shedding slowdown/diameter gains by ~3–6 months, consistent with localized signaling change rather than endocrine remodeling.
4 Add-on to standard care Mechanistically complements minoxidil (growth-phase stimulation) and finasteride/dutasteride(DHT reduction)—potential stacking to reduce required oral 5-ARI dose.
5 Female AGA potential As a non-hormone topical AR blocker, RU58841 is conceptually attractive for female-pattern hair loss where 5-ARIs are often avoided; formal trials are lacking.
6 Sebum/scalp oil AR blockade may reduce sebaceous activity, improving scalp oiliness—evidence is anecdotal/limited.
7 Post-transplant maintenance Hypothesized to protect native hairs around grafts when oral 5-ARIs are not tolerated. Evidence is extrapolative.
8 Hyperandrogenic niches The AR-topical approach is being explored conceptually for acne/seborrhea; RU58841 data are minimal, but class logic supports testing.
9 Quality-of-life Hair density/diameter improvements correlate with appearance satisfaction; validated PRO data for RU58841 specifically are scarce.

2. Molecular Mechanism of Action

2.1 Receptor pharmacodynamics

  • Target: Androgen receptor (AR) competitive antagonist (non-steroidal, flutamide/bicalutamide-like scaffold).

  • Follicular action: Blocks DHT-bound AR signaling in dermal papilla cells, down-shifting transcription of TGF-β, DKK-1, and pro-miniaturization genes, helping maintain anagen and shaft caliber.

  • Selectivity goal: High local AR occupancy with low systemic levels when delivered as a topical solution.

2.2 Down-stream biology

Pathway Functional outcome Context
AR antagonism ↓ Miniaturization signaling Hair follicle DP/ORS
Paracrine growth factors ↑ Pro-anagen milieu (VEGF/IGF-1 balance) Peri-follicular
Sebocyte AR tone ↓ Sebum output (theoretical) Scalp skin

3. Pharmacokinetics (what’s known)

  • Route: Topical solution (commonly 5–10% in ethanol/PG or glycol vehicles in research use).

  • Absorption: Low systemic exposure reported in early studies at clinical doses; depends heavily on vehicle, % concentration, scalp integrity, and application area.

  • Metabolism: Rapid local distribution; specific human metabolites are poorly characterized in public literature.

  • Dosing used in studies: Once-daily topical application; dose-finding suggested ~50–100 mg/day ranges in legacy programs.

4. Evidence Summary

  • Preclinical: In hamsters/macaques, topical RU58841 prevented androgen-driven alopecia and restored hair density vs vehicle.

  • Human (early-phase): Small, short-duration studies reported improved hair counts/diameter with acceptable local tolerability and no meaningful changes in serum hormones at studied doses. Full peer-reviewed datasets remain limited compared with minoxidil/finasteride.

Evidence quality note: Signals are promising but preliminary. There are no contemporary, large, randomized Phase 3 trials; long-term safety and durability are unknown.

5. Where it might fit (conceptually)

Scenario Rationale Caveats
Men intolerant to 5-ARIs Keep DHT systemic effects intact while blocking AR locally Efficacy may be less than oral 5-ARI; purity variability
Stack with minoxidil Orthogonal mechanisms (growth promotion + AR block) Additive irritation risk (EtOH/PG)
Micro-dose 5-ARI + RU Lower systemic exposure while maintaining control Unproven optimal ratios
Female AGA Avoid systemic antiandrogens; local AR targeting Pregnancy avoidance; data sparse

6. Safety and Tolerability

  • Local: Erythema, burning, itch, dryness, contact dermatitis (often vehicle-related); consider propylene-glycol-free or liposomal vehicles.

  • Systemic (intended to be low): Early studies showed no significant changes in serum DHT, T, LH/FSH at studied doses; however, formulation and over-application can increase absorption.

  • Endocrine/sexual AEs: Much less likely than with oral 5-ARIs but not impossible if systemic exposure occurs.

  • Ocular: Avoid contact with eyes.

  • Women of child-bearing potential: Avoid use in pregnancy (class antiandrogen precaution).

  • Unknowns: Chronic use (>1–2 years), rare idiosyncratic reactions, long-term scalp microbiome effects.

  • Product quality risk: Gray-market powders/solutions show variable identity and stability; degradation or mislabeling is a real safety issue.

Comparative matrix (AGA therapies)

Feature RU58841 (topical AR antagonist) Finasteride (oral 5-ARI) Dutasteride (oral) Minoxidil (topical)
Primary action Blocks AR locally ↓ Scalp/systemic DHT Stronger DHT suppression ↑ Anagen, vasodilatory
Systemic hormone change Minimal (intended) Yes (DHT ↓) Yes (DHT ↓↓) No
Sexual AEs risk Low (intended) Low–mod (systemic) Mod (systemic) None sexual
Evidence strength Early-phase, limited Robust RCTs Strong (off-label AGA) Robust RCTs
Use in women Potential (caution) Generally avoided premenopause Avoided Yes (2–5%)

7. Regulatory Landscape

  • Not approved by FDA/EMA/PMDA for any indication.

  • Appears in old patents and early studies; current availability is research-chemical only in many regions.

  • No standardized, GMP-grade medicinal product exists for routine clinical prescribing.

8. Practical Use (harm-reduction guidance for research contexts)

  • Vehicle matters: Ethanol/propylene glycol improves penetration but raises irritation; newer PG-free, liposomal, or hydroalcoholic bases may improve comfort.

  • Application: Once daily to dry scalp, thin film over affected zones; avoid dripping onto face/neck.

  • Stacking: If combined with minoxidil, separate by ~10–15 min; if used with oral 5-ARI, consider lower 5-ARI dose.

  • Monitoring: Track photographs, hair counts/diameter (trichoscopy), and any systemic symptoms. Discontinue if persistent irritation or systemic side effects appear.

  • Sourcing caution: Only laboratories should handle verified material (identity by HPLC/LC-MS/NMR); avoid consumer self-experimentation with unverified products.

Selected References

  • Preclinical AGA models (hamster/macaque) demonstrating topical AR antagonism and follicular protection.

  • Early human studies and patent data showing hair-count improvements with minimal hormonal changes at studied doses.

  • Reviews on androgen signaling in hair follicles (TGF-β, DKK-1, DP cell pathways) and comparisons with 5-AR inhibitors and topical antiandrogens.

  • Formulation/permeation literature on scalp delivery and vehicle-driven absorption for antiandrogen topicals.