RU58841 (PSK-3841) is a non-steroidal androgen receptor antagonist, initially intended for use in treating prostate cancer. However, it has been found to have a noteworthy impact on aiding hair regrowth.
Androgen receptor (AR) is a type of nuclear receptor that is activated by binding of either of the androgenic hormones testosterone or dihydrotestosterone in the cytoplasm and then translocating into the nucleus. Upon binding the hormone ligand, the receptor dissociates from accessory proteins, translocates into the nucleus, dimerizes, and then stimulates transcription of androgen responsive genes. The androgen receptor is most closely related to the progesterone receptor, and progestins in higher dosages can block the androgen receptor. The main function of the androgen receptor is as a DNA-binding transcription factor that regulates gene expression. Androgen regulated genes are critical for the development and maintenance of the male sexual phenotype. Mutations in this gene are also associated with complete androgen insensitivity (CAIS).
RU58841 (Roussel Uclaf) is a nonsteroidal topical antiandrogen without significant systemic effects apparently due to its metabolism in the skin. This appears to be a promising new hair growth agent that promotes hair growth on the scalp as well as retards hair growth of both beard and body hair follicles. RU58841 has produced highly efficacious results in stumptailed macaques.
The synergistic effects of RU58841 and minoxidil topical solution (2% and 5%) have also been reported in stumptailed macaques. The effect of combined treatment was most remarkable early on, but by 1 year no significant benefit of combined treatment was apparent relative to either treatment alone.
RU-58841 is supplied as a crystalline solid. A stock solution may be made by dissolving the RU-58841 in the solvent of choice. RU-58841 is soluble in organic solvents such as ethanol, DMSO, and dimethyl formamide (DMF), which should be purged with an inert gas. The solubility of RU-58841 is approximately33 mg/ml in ethanol and DMF and approximately 25 mg/ml in DMSO.
RU-58841 is sparingly soluble in aqueous buffers. For maximum solubility in aqueous buffers, RU-58841 should first be dissolved in ethanol and then diluted with the aqueous buffer of choice. RU-58841 has a solubility of approximately 0.16 mg/ml in a 1:5 solution of ethanol:PBS (pH 7.2) using this method. We do not recommend storing the aqueous solution for more than one day.
Since RU58841 has not passed into phase two of drug development, there are literally no studies that have highlighted the side effects of this medication specifically.
Pharmacologically speaking, there are absolutely no pharmacologic products that are 100% free of side effects. Like with every medication, RU58841 also affects each individual differently.
But based on the physiologic processes it undergoes, we can hypothesize on some of its potential side effects. For instance, you should be aware that RU58841 does not only block DHT but all other androgens including testosterone.
1. Battmann, T., Bonfils, A., Branche, C., et al. RU 58841, a new specific topical antiandrogen: A candidate of choice for the treatment of acne, androgenetic alopecia and hirsutism. J. Steroid Biochem. Mol. Biol. 48(1), 55-60 (1994). DOI:
10.1016/0960-0760(94)90250-X 2. Obana, N., Chang, C., and Uno, H. Inhibition of hair growth by testosterone in the presence of dermal papilla cells from the frontal bald scalp of the postpubertal stumptailed macaque. Endocrinology138(1), 356-361 (1997). DOI:
10.1210/endo.138.1.4890
RU-58841 is a non-steroidal antiandrogen that binds to the androgen receptor (Kd = 1.8, 1.1, 5.6, 1.3, and 1.4 nM for human, rat, mouse, hamster prostate, and hamster flank organ receptors, respectively). In vivo, topical administration of RU-58841 (1-100 μg per animal) reduces size of the flank organ without affecting sex organs in a dose-dependent manner in hamsters. It has no effect on sex organ weight in intact rats when administered percutaneously, subcutaneously, or orally at doses up to 1 mg per animal. RU-58841 (5% v/v) also induces hair regrowth in the bald frontal scalps of postpubertal stumptailed macaques, a model for male pattern baldness.
Avoid hair loss: RU58841 is a non-steroidal antiandrogenic medication that was initially developed in the 1980s as a topical treatment remedy for acne and male pattern baldness – androgenetic alopecia.
RU 58841, is a specific androgen receptor antagonist or anti-androgen, that has shown to have effect on hair growth.
RU58841 is active against baldness and is commercially available. The previously reported synthesis uses phosgene, three discrete inert atmosphere steps and three steps that require flash chromatography. Our synthesis uses no phosgene, only one inert atmosphere step and does not require flash chromatography.
Alternative synthesis of the anti-baldness compound RU58841
A bromine–nitro substitution at tertiary carbon and using 2-nitropropane as leaving group enable a short phosgene-free synthesis of RU58841.
pubs.rsc.org
Androgens are mainly produced in the adrenal glands and testes. They are male hormones responsible for sex-related development. The well-known androgen is testosterone. Dihydrotestosterone (DHT) is also an androgen, which is a byproduct of testosterone. Although DHT is important for male development and physical health, it can cause hair loss. RU58841 is a topical anti-androgen drug that counteracts the effects of dihydrotestosterone (DHT) by binding to the androgen receptors of the hair follicles, preventing DHT from interacting with the androgen receptors of the hair follicles. Therefore, the hair shrinkage process does not begin, ensuring that the hair undergoes a normal growth cycle.
