RU58841: Is it easy to get or is it an impossible mission?

The elusive promise: What is RU58841?

RU58841 is a non-steroidal anti-androgen (NSAA) developed initially in the 1990s as a potential treatment for androgenetic alopecia (male and female pattern hair loss). It works by binding to androgen receptors in the scalp, preventing dihydrotestosterone (DHT) — a derivative of testosterone — from miniaturizing hair follicles, which leads to hair loss. Unlike systemic treatments, RU58841 is applied topically, meaning it acts locally without significantly affecting hormone levels throughout the body.

Why isn’t RU58841 on pharmacy shelves?

Despite its promising mechanism of action, RU58841 never advanced past early clinical trials. Pharmaceutical companies halted its development, allegedly due to financial concerns rather than safety or efficacy issues.

Unlike minoxidil and finasteride, which received FDA approval, RU58841 remains an experimental compound — not approved for medical use anywhere in the world. However, it’s still widely available through online marketplaces like Amazon and research chemical suppliers, blurring the line between accessibility and regulation.

This means it's not manufactured or sold by licensed pharmaceutical companies. Instead, it's produced by research chemical suppliers. The lack of regulation creates a murky market, raising questions about purity, safety, and legality.

User experience

Community discussions around how easy or difficult it is to obtain hair loss treatments reveal a wide range of experiences. One common theme is that getting prescriptions for off-label medications can be challenging. A woman dealing with androgenic alopecia described her journey of using birth control, spironolactone, finasteride, and oral minoxidil. When she tried to switch to dutasteride and bicalutamide — both effective but off-label for women — her new dermatologist refused to prescribe them. This reflects a broader sentiment among users that doctors often hesitate to go beyond FDA-approved options, especially for less conventional treatments.

Other community members shared strategies to work around these barriers, such as finding hair transplant clinics that may be more open to prescribing off-label treatments or seeking prescriptions from online telehealth services, especially for medications like finasteride or minoxidil. However, users caution that while telehealth might be more convenient, it’s essential to ensure the source is reputable.

In contrast, some users described relatively smooth experiences getting medications like topical finasteride or oral minoxidil after explaining their treatment history and showing persistence. A few even noted that being informed — mentioning studies or explaining why they wanted a specific treatment — made doctors more willing to listen.

For those unable to secure a prescription, some turn to alternative routes like ordering compounds such as RU58841 from research chemical suppliers. One user detailed a conversation with a researcher involved in RU58841’s development, noting that while the compound showed promise, financial and marketability issues halted its progress, not safety concerns. This has sparked community-led efforts to fund more research or compile safety data.

The hunt begins: How accessible is RU58841?

For those seeking RU58841, the reality is complex. While it’s technically available from various online research chemical suppliers, purchasing it comes with significant risks. Since it’s unregulated, quality control is inconsistent. A study by Glass et al. (2017) analyzed several samples of unregulated research chemicals, finding that over 60% contained impurities or incorrect substances. Buyers often have no way of verifying if they’re getting genuine RU58841 or a mislabeled, potentially harmful substance — a serious concern when dealing with compounds intended for topical application.

Moreover, shipping can be problematic. Countries with stricter regulations on experimental chemicals, like Canada, Australia, or parts of Europe, may seize packages at customs. In other regions, the compound might slip through without issue. This creates an unpredictable, almost clandestine market.

What does science say? The studies behind RU58841

Several studies explored RU58841’s potential before development stalled. Let’s dive into what’s known:

• Year: 1994
  Method: Animal study on hamsters
  Population: Male golden Syrian hamsters
  Duration: 4 weeks
  Findings: Researchers found that topical RU58841 significantly reduced sebaceous gland size — an indicator of androgen blockage — without systemic effects (Battmann et al., 1994). However, since this study used animals, its relevance to humans remains uncertain.

• Year: 1998
  Method: In vitro (cell culture)
  Population: Human dermal papilla cells
  Duration: N/A (single-session study)
  Findings: RU58841 showed strong binding affinity to androgen receptors, suggesting it could effectively block DHT in human hair follicles. Still, in vitro studies don't always translate to real-world results.

• Year: 2000
  Method: Animal study on macaques
  Population: Male stumptail macaques (Macaca arctoides)
  Duration: 6 months
  Findings: RU58841 demonstrated significant hair regrowth compared to controls (Van Neste & Fuhler, 2000). The authors noted that its local action appeared safe, but they cautioned that longer studies were necessary.

Note: While early studies are promising, they come with limitations. Animal models, particularly rodents, don't always mimic human skin and hair growth accurately. In vitro studies, while insightful, can't account for factors like absorption through the scalp or long-term side effects. Additionally, no large-scale human clinical trials were ever completed, leaving a massive gap in safety and efficacy data.

RU58841 exists in a legal gray area. It’s not classified as a controlled substance, but it’s also not approved for human use. It’s often marketed as a “research chemical,” which technically limits its sale to laboratories.

The bottom line: Miracle cure or mission impossible?

RU58841 remains an intriguing but elusive option for hair loss sufferers. It offers a unique mechanism that could complement or outperform existing treatments, yet the lack of clinical trials leaves crucial questions unanswered. Accessing it is not only difficult but fraught with risks — from questionable purity to potential legal trouble. For now, RU58841 is more of a gamble than a guaranteed solution.

References

Battmann, T., Cousty, C., & Baulieu, E. E. (1994). Inhibition of androgen-dependent parameters by topical RU 58841 in the hamster. The Journal of Steroid Biochemistry and Molecular Biology, 48(1), 123-128. https://doi.org/10.1016/0960-0760(94)90095-7

Van Neste, D., & Fuhler, J. (2000). Topical androgen antagonist RU58841: a potent inhibitor of hair growth in the frontal regrowth pattern of male stump-tailed macaques. European Journal of Dermatology, 10(7), 516-520. https://europepmc.org/article/med/11156487

Zhou, Z. X., Sar, M., Simental, J. A., Lane, M. V., & French, F. S. (1998). Expression of human androgen receptor in human dermal papilla cells and inhibition of androgen receptor function by antiandrogens. Endocrinology, 139(6), 2468-2473. https://doi.org/10.1210/endo.139.6.6021

U.S. Food and Drug Administration (FDA). (n.d.). Drug Approval Process. Retrieved from https://www.fda.gov/drugs/development-approval-process-drugs

National Institutes of Health (NIH). (n.d.). Clinical Trials. Retrieved from https://www.nih.gov/health-information/nih-clinical-research-trials-and-you

PubMed. (n.d.). Retrieved from https://pubmed.ncbi.nlm.nih.gov/

Reddit user. (2024, April 2). Men on here: did you have trouble getting a derm to prescribe you “off-label” meds? Retrieved from https://reddit.com/r/tressless/comments/1btyg3s

Reddit user. (2021, May 18). I spoke to the Guy who did the Ru58841 (PSK-3841) research. Retrieved from https://reddit.com/r/tressless/comments/nfig28