RU58841 for Hair Loss: A Powerful Androgen Receptor Blocker -

RU58841 for Hair Loss: A Powerful Androgen Receptor Blocker

Male pattern hair loss is caused when the hormone DHT binds to receptors in the hair follicles. RU58841 competes with DHT to bind with the receptors and as a result less DHT binds and therefore hair loss is reduced.

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Last updated: Nov 3, 2023


Androgenic alopecia is an androgen-dependent condition caused by the binding of DHT to the androgen receptor. A person predisposed to androgenic alopecia shows high levels of DHT and an increased expression of the androgen receptor.

Clinical treatment with anti-androgens, whether taken orally or through topical application has been proven to be relatively successful. (Trueb, 2002) Among them, the anti-androgen RU58841 seems to be a promising drug that may help people suffering from androgenic alopecia as well as other androgen-related conditions.

Before analysing the various studies that are linked to RU58841 it is important to mention that this drug hasn’t been approved and there aren’t any trial studies showing its real effects on hair loss. It is also still classified just as a chemical, but available for purchase online for research.

RU58841 is a non-steroidal anti-androgen topical treatment that has been researched for years to be used as a hair loss treatment and in the treatment of other androgen-dependent skin diseases such as acne and hirsutism. It seems that acne and androgeic alopecia are both linked to androgen effect; it has been speculated and shown in various studies that anti-androgens have a beneficial effect in patients experiencing hair loss with topical application of anti-androgens such as RU58841.

Several studies strongly indicate RU58841 is an effective hair loss treatment

The grafts that were treated with a solution of RU58841 had a total of 29 active follicles while the control grafts had two follicles

The RU58841 anti-androgen has a high affinity for the androgen receptors in the hamster prostate and flank organ and has a dose-dependent effect when applied topically. (Battman et al., 1994) Another study (Miyamoto, et al., 1996) states that hormone therapy can be used for the treatment of prostate cancer and some antiandrogens may act as androgen receptor antagonists. It also mentions RU58841 has good anti-androgen properties, which makes it a viable candidate as a treatment for other androgen-dependent diseases.

Even more studies confirm the efficacy of the treatment: Teutsch et al., (1994) suggest that RU58841 may be useful as specific markers in the treatment of male pattern baldness or acne, among others. In fact, the paper states, RU58841 is also without any antagonistic effect and has no specific binding to human plasma.

How does RU58841 work?

the results showed that the topical application of RU58841 not only increased the hair density but also its thickness and length

RU58841 is considered to be one of the most promising drugs regarding hair loss prevention and it’s also available commercially for those who want to try the drug on their own; but as a treatment, there have been no trials to this date (Jan 2020). However, there are testimonials online from people who have undergone the treatment independently and had positive results, but without any official clinical trials and an approved drug, RU58841 has very little chances to become the newest treatment against hair loss any time soon.

To study the effect of the RU58841 on human hair growth, researchers (Brouwer et al., 1997) used twenty productive scalp grafts from bald men. These were maintained for 8 months and grafted to nude mice in order to monitor the hair production process. The monitoring lasted for 6 months, during which time a topical solution of testosterone was applied. Some of the scalp samples were treated with a topical solution of RU58841 for 5 days a week while other scalp samples were treated with a solution of ethanol as a control. The results showed the efficacy of the RU58841 in hair growth. The grafts that were treated with a solution of RU58841 had a total of 29 active follicles while the control grafts had two follicles. Among the active follicles, 28% of the RU58841 treated follicles showed a second cycle while in the control group, only 2 follicles initiated a second hair cycle. The study concluded that the value for linear hair growth rates was significantly higher in the group treated with the RU58841 and this particular product may be used in the treatment of androgen-dependent alopecia successfully.

Another study (Pan et al., 1998) was focused on RU58841 as an anti-androgen in prostate PC3 cells as well as a topical anti-alopecia agent in the bald scalp of the stump-tailed macaques. When it was used as an anti-alopecia agent, the results showed that the topical application of RU58841 not only increased the hair density but also its thickness and length. The authors concluded that the RU58841 anti-androgen could be a great candidate in the treatment of androgen-dependent skin disorders.

RU58841 may be beneficial for sebum related alopecia

the authors concluded that RU58841 + myristylchloride should definitely be considered as a treatment for topical anti-androgen therapy of acne and androgenic alopecia

A study on fuzzy rats, a mutant rat between the hairless and hairy albino rat, examined the role and effect of the androgen receptor blocker RU58841 on regression of glandural and ductal hyperplasia. This particular mutant rat had androgen-dependent hypersecretion of sebum as well as hyperplastic sebaceous glands along with 2 other agents: MK386 and finasteride. The agents were dissolved into propylene glycol, alcohol and water and applied on the backs of peripubertal male rats for 2 months. There were two other groups, one castrated and a control one that only received the vehicle solutions (propylene glycol, alcohol and water) without any agent. The results showed that RU58841 induced glandural and ductal regression equivalent to that in castrates and also a reduction of BrdU-positive cells. The agent RU58841 also counteracted endogenous androgens which resulted in a suppression of growth of the sebaceous glands but not the prostate. The authors conclude that this model for androgen-dependent hyperplasia can be useful in further study.

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RUM: An improved version of RU58841

In 2003, a study showed how an improved RU58841 would be an even better potential treatment for hair loss. The drug was incorporated with myristyl chloride and this new type of drug was called RUM. The authors checked RUM for penetration and permeation and in order to improve the targeting of the hair follicles the substance was loaded on solid lipid nanoparticles. After permeation and penetration tests the authors concluded that RU58841 + myristylchloride should definitely be considered as a treatment for topical anti-androgen therapy of acne and androgenic alopecia. (Munster et al., 2005)

Imamura et al. states that RU58841 also prevents androgenic follicular regression in stump-tailed macaques but doesn’t promote the follicular cell growth — at least not in a direct way. The best effects in their study were observed on the group receiving an additional Minoxidil 5% along with the RU58841 for both hair regrowth and hair persistence.

Certain companies have been taking an interest in RU58841 and the drug became known also as PSK-3841. Proskelia, a French company started investigating the drug and it seems to have been in Phase II clinical trials in January 2004. The trial ended in 2005 but no news has been released concerning it. (Guénolé, 2004, retrieved 2016)
A benefit when using RU58841 according to the scarce research that has been done is the fact that there are no known side effects. When the drug is applied on the scalp it is able to penetrate the skin easily and reach the hair follicles without entering the bloodstream. (RU58841 : Independent Information, retrieved 2016)

Unfortunately, there have been no further attempts to bring back RU58841 or any attempts to study it as a viable option for androgen-related diseases, but the compound still exists and it is frequently reviewed by independent sources testing it, on its own or in a combination with Minoxidil 5%. However, testing the product on your own without proper medical advice would imply some risks which may be linked to the possible side effects of this compound or the quality standard of your supplier.

Where to buy RU58841

RU58841 is currently not approved for use by humans and considered a “research-only” compound. However, as a research compound, it is available to buy from several online stores. Just search “buy RU58841”. I also have some available in pure form and in pre-mixed solutions with 8% Minoxidil, Sandalore, peppermint oil, velvet deer antler, carnitine, apigenin, Red Korean gingseng, capsaicin, luteolin, cetirizine and lactobacillus. I consider this to be an incredibly good (perhaps the best) topical hair loss treatment. If you’re interested in purchasing a bottle, or just the pure RU58841, please contact me.

RU58841 on!

I was amazed to recently see an RU58841 topical solution being sold on Amazon:

RU58841 topical spray

I don’t know how long that product will be available, so if the link’s broken when you see it, my apologies in advance. There must be a lot of demand for RU58841 for so many products to be cropping up all over the internet and now even one on Amazon being sold as a hair loss treatment.

Is RU58841 safe?

RU58841 hasn’t been tested on humans. Although the laboratory tests have shown very promising results on human hairs, no clinical trials have been conducted on human subjects to date (as far as I know). So no one knows for certain whether RU58841 is safe for human use. The only evidence we have that it’s safe is testimonial evidence from people who claim to use the chemical to prevent hair loss — and there are quite a lot of people who are experimenting with it. You can buy RU58841 online and quite a few people have posted their personal experiences using the chemical and many of them claim it’s incredibly effective.

Evidence that it’s safe

It’s believed that RU58841 works by binding with androgen receptors in the scalp rather than by reducing DHT. DHT causes hair loss in the scalp when it binds with androgen receptors in the hair follicles. RU858841 seems to reduce the number of available receptors, restricting DHT from damaging the follicles.

Since RU58841 acts on the receptors and not DHT, it’s hypothetically reasonable to assume that the chemical will be less damaging to the body overall, compared with Propecia, which is consumed orally and can, therefore, affect many different parts of the body, rather than just the scalp.

Generally speaking, treatments that are applied to the scalp should have less adverse side effects than treatments administered orally.

Is RU58841 FDA approved?

RU58841 is not FDA approved and there are doubts as to whether it will ever get approval for use as a hair loss treatment. Like many drugs, there may be potentially harmful side effects. As far as I know, the drug has never gone through clinical trials on humans.

Despite this a lot of people are using RU58841 for hair loss and they’re buying the drug from websites that sell it as a “research chemical”.

References and further reading

  1. Ralph M Trüeb, Molecular mechanisms of androgenetic alopecia, Experimental Gerontology, Volume 37, Issues 8–9, 9 August 2002, Pages 981-990, ISSN 0531-5565, (
  2. T. Battmann, A. Bonfils, C. Branche, J. Humbert, F. Goubet, G. Teutsch, D. Philibert, RU 58841, a new specific topical antiandrogen: A candidate of choice for the treatment of acne, androgenetic alopecia and hirsutism, The Journal of Steroid Biochemistry and Molecular Biology, Volume 48, Issue 1, January 1994, Pages 55-60, ISSN 0960-0760, (
  3. Miyamoto, H., Yeh, S., Wilding, G., & Chang, C. (1998). Promotion of agonist activity of antiandrogens by the androgen receptor coactivator, ARA70, in human prostate cancer DU145 cells. Proceedings of the National Academy of Sciences of the United States of America, 95(13), 7379–7384.
  4. G. Teutsch, F. Goubet, T. Battmann, A. Bonfils, F. Bouchoux, E. Cerede, D. Gofflo, M. Gaillard-Kelly, D. Philibert, Non-steroidal antiandrogens: Synthesis and biological profile of high-affinity ligands for the androgen receptor, The Journal of Steroid Biochemistry and Molecular Biology, Volume 48, Issue 1, January 1994, Pages 111-119, ISSN 0960-0760, (
  5. Münster U; Nakamura C; Haberland A; Jores K; Mehnert W; Rummel S; Schaller M; Korting HC; Zouboulis ChC; Blume-Peytavi U; Schäfer-Korting M (January 2005). “RU 58841-myristate–prodrug development for topical treatment of acne and androgenetic alopecia”. Pharmazie. 60 (1): 8–12. PMID 15700772.
  6. De Brouwer, B., Tételin, C., Leroy, T., Bonfils, A. And Van Neste, D. (1997), 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 mice. British Journal of Dermatology, 137: 699–702. doi:10.1046/j.1365-2133.1997.19382053.x
  7. Pan, H., Wilding, G., Uno, H. et al. Endocr (1998) 9: 39. doi:10.1385/ENDO:9:1:39
  8. Retrieved 2016
  10. Imamura, K. et al., The effect of topical RU58841 (androgen receptor blocker) combined with minoxidil on hair growth in macaque androgenetic alopecia , Journal of Dermatological Science , Volume 16 , S207
  11. retrieved 2016