RU58841 for Hair Loss – Underused Finasteride Alternative?

Bonnke Arunga, MBBS

By    – Updated on May 2, 2021 – Reviewed by dermatologist Dr. Suneil Gandhi, MD

bottle of ru58841 and its formula

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The process of managing your hair loss is often frustrating. You may bank on a particular product, but it fails to yield the results you were desiring.

Meanwhile, your hair is reducing fast. Well, you should not be worried when this is happening to you. Because in the area of hair loss, you are indeed not alone.

Several medications are available for treating hair loss. Unfortunately, none of them work magically to restore your full head of hair. That is why there are numerous treatment options.

What is RU58841?

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.

RU58841 goes by several names. You might have come across names like PSK3841 or HMR 3841. All these mean the same thing, just different companies manufacturing them.

ru 58841 white powder

As a result, it has gained increased attention even among individuals who seem to have exhausted all other treatments for hair loss.

However, one must take this with a pinch of salt – there are inadequate scientific studies that validate this claim. Most of the stories that you read on the internet are claims from individuals who may have a conflict of interest or are on other hair loss medications such as minoxidil and finasteride.

How did it come about?

The concept of RU-58841 is not an invention of the recent past. The idea to develop it was first put forward by French scientists way back in the 70s. Although it had been produced in the 80s, most of the research about its development progressed into the 90s.

The main aim of these scientists was to develop a potent medication that would effectively manage acne and androgenic alopecia when applied topically while avoiding/limiting systemic side effects.

Rats and hamsters were the animal models used to test its effectiveness. During the trial phase of the mediation, the RU58841 results were very promising.

Actually, even small doses as low as 0.001 milligrams showed significant local effects. Even at high doses of up to 0.01 milligrams, the action was still limited to the site of application – a much-desired relief for the researchers.

A lot has transpired since the inception of the idea. For instance, several companies have acquired and dropped their right to this product. Eventually, one company – ProStraken – acquired the full rights to RU58841 and changed its name to PSK3841.

Much later in 2005, ProStraken announced that they would push the medication to a phase two trial and hopefully launch the product in 2010. Fast forward to today, it is not clear whether the phase two trial ever took place.

There are very limited developments around this product. Consequently, the FDA has not approved it for the management of any condition so far.

The science behind it

Since this medication is anti-androgen, it may be able to target skin conditions such as acne and androgenic alopecia.

However, the mechanism of RU58841 is entirely different from other anti-androgenic medications. And here is the reason:

Unlike other antiandrogenic drugs that act by either reducing or blocking the synthesis of dehydroepiandrosterone (DHT) and testosterone, RU58841 mainly works with particular specificity to the receptor.

Right now, you are probably aware that hair loss occurs due to the action of DHT and testosterone. RU58841 competitively binds to the receptors of DHT thus blocking any DHT from attaching to the receptors and causing hair loss.

How effective is RU58841?

The effectiveness of RU58841 is quite impressive. The overall effect is really noticeable as can be seen in this RU58841 before and after comparison below.

r58841 hair regrowth before after
Great RU58841 Responder 1 (Source:

Evaluating the effectiveness of RU58841 will make us compare it to medications such as finasteride which inhibits or reduces the synthesis of DHT.

The mere fact that the effect of RU58841 does not interfere with the synthesis of DHT and testosterone makes it a very promising drug. What’s more, you will not be worried about side effects such as erectile dysfunction, which is relatively common with finasteride.

ru58841 hair regrowth on male
Great RU58841 Responder 2 (Source:

I am not in any way suggesting that finasteride is ineffective. The drug reduces a significant part of your DHT, so you will not have to worry anymore about as intensive hair loss as it was before.

This is where RU58841 works differently. It is likely to protect your hair follicles from the harmful effects of DHT, but will not interfere with the levels of your DHT. All the benefits of DHT are left intact when you use RU58841.

How to use RU58841?

The most exciting part is knowing how to dose this medication and how to store it. As previously mentioned, initial trials on this medication revealed that it is very potent even at low doses. When all things are put at a constant, a daily dose of 50 mg applied in areas that are affected by alopecia will suffice.

However, certain underlying intrinsic factors may prompt an individual to use more than 50 mg. For most of the people I have interacted with, none of them has seen the need to use more than 50 mg.

While you are at liberty to increase the dosage to between 75mg and 100 mg per day, you will soon realize that it is absolutely unnecessary and may be an economic disadvantage as you waste your precious medication.

Here is how to use it

man using dropper to apply hair loss solution

Apply 50mg of the medication in the areas that have suffered hair loss. Then, rub and spread it gently with your fingertips to ensure that it covers the target area evenly.

After you have applied it, let it dry. The liquid will take roughly one minute to dry. The next procedure depends on whether you are using other hair treatments as well. For instance, this is the best time to apply your minoxidil if you are using it too to treat your hair loss.

When should you apply your RU58841?

There is ideally no standard time to apply this medication. But one thing that you should put into account is that your skin always produces a lot of oil called sebum.

This sebum reduces the effectiveness and the penetrative value of RU58841. As a result, you may want to apply it after hitting the shower – preferably within 30 minutes after taking a shower.

man washing his hair

It depends pretty much on what is convenient for you. Some people actually prefer applying it before bedtime at night. And it works really well for them.

While there are no fixed laws about applying RU58841 after the shower, doing so will literally optimize its penetrative value and its overall effectiveness.


The active RU58841 is a water-based formulation, so, you may have to apply it behind the hairline and spread it to cover the target area.

How to store RU58841

The idea behind storing your RU58841 is that you want the efficacy to last longer so that you can use it for a considerable amount of time.

It is recommended that the mixed solutions of RU58841 be stored in a fridge. The raw powder form should be stored in a freezer. Irrespective of how you store it, you should be careful not to expose it to high temperatures or to sunlight because these conditions will degrade the active compound and it will lose its effectiveness.

What are the side effects of RU58841?

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.

This means that if there are any side effects, then they are actually unknown. For now, information about its side effects can only be derived online from the reviews of customers who have actually used the product.

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.

It is hoped that future studies will document the side effects of using RU58841. 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.

Do you know what this means?

In the event that even a drop of this medication lands in your serum, it will interfere with the physiologic activities of all your androgens leading to side effects such as:

  • chest pain
  • dizziness
  • fatigue
  • decreased libido
  • headache
  • erectile dysfunction
  • mood alteration
  • blurred vision

This is the reason why it is advisable that you use RU58841 with great caution. If possible, consult your doctor or healthcare provider before you use this product or when you notice symptoms after using it.

Users reviews of RU58841

There are a lot of reviews online about RU58841. Here are some of the findings from people who have used the product:

The best suppliers

Most people swear by Kane and Anagen Inc. They provide pretty much the same product that looks legit and is an appropriate formulation to start with.

However, the shipping process may make you receive a product that has depreciated in efficacy. As said previously in this text, exposure to heat or light causes degradation of the active ingredient.

Using alongside with other medications

Users report that treatment and recovery from hair loss are heightened if you use ru58842 concurrently with minoxidil. But you may not be able to tell which drug is doing the work of improving your hair loss. Don’t mix the two. Only apply minoxidil after ru8841 has dried in the target area.

How to achieve maximum benefits

If your body doesn’t react negatively to the pre-made formulation, buy the ingredients and the equipment and prepare RU58841 at home. This way, you get to preserve the efficacy. However, it may not have the same effectiveness as a scientifically prepared formulation.

Where to buy RU58841?

Most of the purchases for RU58841 can be made online from several of the most popular suppliers like Chemyo, Kane, and Anagen Inc. Recommendations are that it can only be purchased for the purpose of research or experiments.

As a result, you should actively think through it and decide if it is indeed the medication you want. Once you have made up your mind, choose the 99% pure grade while taking care to read the label carefully so that nothing is appearing out of place.

Another factor you should be aware of is that the medication is not regulated by the FDA. As a result, there are no guarantees that you will get what you see advertised.

Most users have reported that it is effective to purchase the raw ingredients and the equipment so that you can mix it yourself.

Alternatively, you can purchase the pre-made version from Chemyo. Though like any other RU58841 product, it is not FDA regulated.

bottle of RU58841

RU58841 5%, 50ml

  • 5% RU58841 concentration
  • Other ingredients: 70% ethanol, 25% propylene glycol
  • Third-party (laboratory) tested

Buying the ingredients and equipment is expensive. The benefit of pre-made products is that they are cheaper and you may stop if your body reacts negatively to the product. (It would actually be expensive if you stop after purchasing your own equipment and ingredients.)


RU58841 is one of the products that may help you to manage your hair loss. However, the fact remains that it is not recognized or regulated by the FDA. This makes vendors mess around with the concentration and purity of the product.

The best option is to make formulations yourself, but this process is quite expensive. You may not even get a genuinely effective product to begin with. Moreover, RU58841 is only without side effects if it doesn’t get into your bloodstream. If it does, you may suffer unprecedented side effects.

So consult your doctor and consider other tried and tested options for hair loss, like minoxidil, oral or topical finasteride (more widely used RU58841 alternative), or laser light devices, before considering this one.

  • De Brouwer, B., Tetelin, C., Leroy, T., Bonfils, A., & 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(5), 699-702. DOI:
  • A multi-centre, double-blind, randomised, vehicle-controlled study for a quantitative estimation of hair re-growth in male subjects with androgenetic alopecia treated over 6 month with two ethanolic PSK 3841 solutions (2.5% and 5%). 2005. DOI:

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