Does RU58841 Block Testosterone?

One of the challenges with male pattern baldness is the lack of medication for it. This is not necessarily because of the limited availability/effectiveness of the medication. It is because many of these medications have side effects, such as altering androgen levels.

Yes, RU58841 does block the effects of testosterone. However, the effect is localized on the head alone when applied as a topical solution. This localization means that RU58841 will not affect testosterone levels systematically unless it gets absorbed into the bloodstream.

RU58841 is an antiandrogenic compound that inhibits the effects of DHT (more on DHT later). It has significant positive results among users. But it is still a lesser-known form of medication for male pattern baldness.

RU58841 Results. Source: Max Kesik

Word of Warning

Before anything else, you should know that RU58841 is not an FDA approved product. This lack of credibility and validation is due to the lack of research on the compound.

It has been put aside for a bit over a decade now because it breaks down fast and can’t sit in storage for a long time. Because of this, you cannot grab RU58841 at your local pharmacy. RU58841 is only available for “research” purposes.

As such, you should take caution and make informed choices about the product. If you are still unsure, the rest of this article will dive more into the risks of RU58841 so you can make a better choice.

Even so, the compound shows incredible promise for male pattern baldness. There are benefits that you can get from RU58841 that are not available in other medications. Thus, the benefits may outweigh the risks regarding validity and certification.

How Does RU58841 Work?

The antiandrogen RU58841 works to help hair loss by inhibiting the effects of testosterone and DHT (both of which are androgens). Androgens play a large role in the bodily functions of men.

They are the hormones responsible for secondary male sex characteristics such as a deeper voice and facial hair. They are also important in libido and sexual functions.

Now that we have established the importance of androgens, let’s draw our attention to DHT. It’s a product of testosterone when transformed by a certain enzyme called 5-alpha reductase.

As an androgen, DHT does several things for the rest of the body. However, it does not help scalp hair.

The continuous production of DHT causes the hair growth cycle to get cut short. Instead of running through its normal phases, the hair follicles get smaller and smaller. The process is called miniaturization.

This process leads to hair becoming thinner and shorter over time until hair growth is no longer possible. This ordeal leads to a receding hairline and bald spots in men.

What does RU58841 have to do with all that? Well, RU58841 effectively counteracts the effects of DHT and testosterone on the hair follicles.

It does this by interfering with the androgen receptors and intervening with DHT and testosterone’s effects on hair growth. It attaches to the receptors so that other androgens can’t. RU58841 theoretically does not systematically change body hormones, unlike other forms of medication such as finasteride. As a medication for androgenic alopecia, that is quite a significant advantage.

However, to reach your hair follicle, it does have to absorb through the skin, and parts of the medication will always go systemic to some degree.

But RU58841 is unlike other treatments. For one, it does not interfere with 5-alpha reductase. Instead, it directly limits the effects of androgens.

The DHT and testosterone levels of the body will remain the same. We see this in a study by Pan et al. (1998) on stump-tailed macaques.

RU58841 Results. Source: HairLossTalk

Side-Effects of RU58841

RU58841’s main benefit is in how localized it is. But there are still some risks that one can associate with the product. Unfortunately, many people report systemic changes due to the compound.

Take note that RU58841 affects all types of androgens and not only DHT or testosterone. It attaches to androgen receptors and prevents them from doing their job. This is what we want in the hair, but not in the rest of the body. This means there are potential risks and consequences when using the product.

Because there is so little research done on RU58841, there are no conclusive findings of its actual effects, especially in the long term. Thus, although it is effective in theory, RU58841 remains a risky product. If you are picky about safety and want products with a proven track record, RU58841 probably is not the best bet for you.

The side-effects of RU58841 include:

  • dizziness
  • chest pain
  • moodiness
  • vision changes
  • headaches
  • exhaustion
  • low libido
  • and more

Remember, even though RU58841 works at the hair follicle, it can still be absorbed into your bloodstream. Theoretically, it should break down before causing any real damage, but nobody knows for sure. To minimize side effects, avoid putting it on right after a shower after your pores are open. Limit your dosage to once a day.

RU58841 is still very much an experimental compound and has a lot of risks tied to it.

Other DHT Blockers

Fortunately, RU58841 is not the only product on the market that can help with male pattern baldness. Unfortunately, each of these also has a degree of risk associated with them. So it is best to exercise caution and do research first.


Propecia is probably the number one medication choice for androgenic alopecia. Professionals treating male pattern baldness use this as the first line of defense.

It works by stopping 5-alpha reductase from transforming testosterone to DHT. This reduced level of DHT will help with the normal hair growth cycle and will limit miniaturization.

It has a high success rate, and most people will take well to the medication.

However, it is still necessary to consult with your doctor before undergoing any treatment. Especially when you have had no experience with it before. You may have underlying conditions that are not suited for use with the medication.

Plus, finasteride is FDA approved and has research to back its claims. In this study by Shapiro et al. (2003), finasteride was successful in 90% of the participants. That is a huge number and conclusive proof that finasteride does work.

Finasteride Before/After

Finasteride has much more research behind it and is a safer choice than RU58841. However, finasteride affects the body and hormones as a whole. Despite being well-researched, it causes side-effects in some people because it lowers DHT systemically. Also, it doesn’t stop the effects of testosterone on hair follicles. But given the lack of research on RU58841, finasteride seems a safer and more pragmatic choice.

Saw Palmetto

Saw Palmetto is a natural DHT blocker. Indigenous people have used it for the longest time. It’s great because it is a natural alternative that might help with hair loss and help other prostate and bladder problems.

Sadly, there is no conclusive proof about how effective saw palmetto is in battling male pattern baldness. However, it is still effective anecdotally.

Saw palmetto comes from a tree. And companies extract it to create the commercial version of the supplement on the market. As a plus, you can buy it anywhere.

Check out our article on natural hair loss solutions for more info on alternative treatments. For more info on finasteride and minoxidil, check out our main hair loss guide.


RU58841 does block testosterone, but not throughout the body. The medication’s localized effect on the hair is one reason many people are willing to risk taking this drug instead of finasteride. But to have the best chance of combatting hair loss, you should take both (under the supervision of your physician).


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