What is RU58841?

RU58841 is a topical anti-androgen, meaning it blocks the action of testosterone when applied topically. It is also known by different names such as RU-58841, HMR3841 and PSK3841. The molecule compound inhibits the action of dihydrotestosterone (DHT) on hair follicles, potentially slowing or reducing hair loss. Thus, unlike finasteride, it acts on the scalp rather than throughout the body.

Despite promising results in multiple studies showing efficacy in hair regrowth, further research and commercialisation of the molecule compound has not gone ahead. As a result, RU58841 has not been approved by regulatory bodies such as the US FDA and the European Medicines Authority.

Why is it called Ru58841?

Because research on it has been discontinued, no pharmaceutical company has bought its patent or picked up sales of it. So it is known only by the name of its molecular formula. Think of minoxidil, marketed in some countries as Rogaine. Or Finasteride, also sold under the name Propecia.

How does RU58841 work?

Dihydrotestosterone is the main cause of hair loss in men. DHT, a by-product of testosterone, binds to androgen receptors and reduces hair follicles in people who are sensitive to this hormone.

In the 1990s, the first research was conducted on the molecule, which was named RU58841. In it, researchers concluded that it is effective in binding to androgen receptors. This means it may be stronger at blocking the effects of androgens - such as testosterone - than other similar drugs such as finasteride and dutasteride. This could potentially make it a powerful drug for treating conditions caused by androgens. These conditions include hirsutism (unwanted facial hair in women) acne and genetic hair loss in men.

Finasteride is a potent agent that blocks DHT throughout the body, which can lead to significant side effects. RU58841, on the other hand, is applied topically, which means it has less of an impact on hormone levels and works mainly because it blocks androgen receptors locally. This means it prevents male sex hormones from binding to androgen receptors, which are involved in normal hair loss. Although RU58841 effectively blocks this binding without the severe side effects of finasteride, it may have other side effects.

RU58841 side effects

As clinical trials have never been published publicly, we unfortunately only have anecdotal side effects online. However, the most commonly reported side effects are as follows:

• Low libido
• Erectile dysfunction
• Palpitations
• Fatigue
• Insomnia
• Skin rash, skin irritation

RU58841 is available in some countries and through online platforms, but its unclear status raises questions for us about its efficacy, but especially its safety. Moreover, RU58841 has not been tested on humans, only on animals such as monkeys and mice, which makes its reliability and safety for human use very uncertain.

Is RU58841 safe to use?

The development of RU58841 was marked by obscurity. The name has been changed several times and ownership of the patent is unclear. Nobody is pursuing official approval for its use as a hair growth drug, despite interest from the public. As a result, the status of RU58841 is unclear. Its effectiveness is recognised by some, but it does not get beyond anecdotal evidence as a result. Safe and approved use is hampered by regulatory, safety and legal barriers. The fact that it is offered online does not mean it is legal.

RU58841 has been around for more than 30 years, and pharmaceutical companies have effectively abandoned the drug. The why of this can only be speculated about. One fact remains that the drug has not been researched enough, has not been verified by official regulatory bodies, is not officially marketed, and is therefore not safe to use.

It can be frustrating to see no or little results in your treatment for hair loss. So it is understandable if you start looking for alternatives. But RU58841 has only shown results in animal trials and anecdotes. While there are good testimonials online about RU58841, it does not seem to be any better than officially recognised hair growth drugs. Add to that the grey area you find yourself in if you buy it online, and we can only come to the conclusion that we advise against using this remedy.