S23 Review

What is S23? Is it safe for health? What results can you expect from using this product? What should you know before buying it? You will find answers to these and other questions in the following article

What is S23?

S23 belongs to the group of agents called SARMs (Selective Androgen Receptor Modulators). These agents are known to have a selective effect on androgen receptors, resulting in far fewer side effects than anabolic steroids or prohormones. 

sarm s23 capsules

It is rumored that in recent months, a well-known pharmaceutical company – GTX – has started research on this substance. Looking at the number of potential applications, I would not be surprised if it turned out to be true. 

GTX is probably interested in one particular ability of the S23 – to block semen production. S23 may be an alternative to female contraception and the f

irst male contraception available on the market.

Rat studies show that within a few days of starting the S23, the animals became completely infertile. This effect was completely reversible shortly after the discontinuation of S23. 

So far, studies have confirmed the ability of the S23 to increase strength and accelerate muscle mass building without androgenic side effects. This substance also allowed to burn fat tissue much faster. What is more, a reduction of the prostate was observed during the use of this product, which is excellent news for people with this problem. 

As a result of these advantages, S23 has been gaining great popularity among athletes all over the world in recent years. However, it should be remembered that most of the current studies were conducted on animals, and their results do not always translate 1:1 to humans. 

S23 Benefits

  1. Aids in building up a lean body mass
    S23 is one of the most potent SARMs currently available on the market. It allows you to build muscles and burn fat at the same time, so that even with a calorie surplus, instead of the typical bulk you will experience rather a recomposition.
    Results from rat studies show that the S23 simultaneously reduced the level of body fat and total body weight.
    Scientists also gave the rats estrogens so as to encourage them to have intercourse and see if they would lose muscle mass as a result. Instead of the expected results, the rats given S23 gained extra muscle tissue, while at the same time displacing the estrogen action.
    Research has also shown that S23 can prevent muscle damage caused by glucocorticoids. It is a powerful anti-inflammatory drug whose chronic use reduces the amount of muscle tissue. SARM administration counteracted the adverse effects of glucocorticoid, increasing muscle mass, and improving strength and endurance.
  2. Increases strength and durability
    The S23 testers experience a significant improvement in strength and endurance in the first weeks of the cycle.
    Increased endurance means you can train longer and harder – which translates into better training results.
    Remember that regardless of the substances used, training and diet always play a key role. SARMs or steroids are only a tool that makes it much easier to achieve the desired results.
  3. May act as a contraceptive for men
    All over the world, there is active research in the search for oral contraceptives. S23 is one of the candidates on which pharmaceutical companies have been focusing more and more often in recent months.
    Studies in rats show that it is able to temporarily block the hormones responsible for signaling the production of sperm – LH, and FSH.
    Current results show that the results are temporary and that after the discontinuation of the drug, the production of sperm returns to its base value within a short period of time.
    However, if you want to try it, you should pay special attention to choosing the right dosage. Rat studies show that individuals who have taken much higher doses than normal had normal or higher than baseline sperm production.
  4. Does not cause increased water retention
    According to reviews of users, S23 does not cause any water retention. This means that with proper nutrition and PCT, you can maintain 100% of your weight after the cycle. Also, as is widely known, increased water retention has a negative impact on the aesthetics – especially on the face. 
  5. Increases libido in women
    Currently, this effect has been examined only in case of reduced libido caused by menopause. The problem is known as hypoactive sexual desire disorder (HSDD) and is usually treated with testosterone. Unfortunately, this type of therapy can have side effects, such as lowering the voice or enlarging the clitoris.
    Unlike testosterone, S23 improves libido without androgenic side effects. 
  6. Harder muscles
    This substance not only increases muscle hardness but also improves their appearance. During the cycle, you can experience a dry mass effect similar to Anavar or Trenbolone. For this reason, it has often been used in preparations for competitions. (It is currently on the WADA list, so it cannot be used by professionals.)

Side Effects

Unfortunately, although SARMs usually do not have any side effects or have ones that are not very troublesome, in S23 case it looks a bit different. Despite its selective effect, this substance affects receptors in a way that can be quite bothersome.

  • Reduced testosterone production
    According to some users, S23 is the closest to the steroid that can be legally purchased. Unfortunately, the strength of this substance has a cost. Reduced testosterone production is a result of HPTA axis suppression. This means that after the cycle is over, PCTs often have to be performed as with anabolic steroids. 
  • Shrinkage of the testicles
    This effect is related to the impact of SARM on LH. Decreasing the amount of hormone production causes the cessation of sending signals to Leydig cells. As a result, the testicles reduce production and decrease their volume. This side effect can be prevented by using HCG.
    This is a temporary effect. After cycle testicles return to their normal size.
  • Darker urine
    In some reviews, testers have noticed a darker urine colour. This is a temporary effect and passes within about 2 days after discontinuation. These people did not notice any abnormal results of liver, creatinine, or urea tests, so this effect is most likely due to the presence of some metabolite S23, which is excreted in the urine.
  • Increased aggression
    I’ve heard opinions that S23 can increase aggression. Of course, it is very possible that in some cases it does, but the truth is that these opinions are often grossly exaggerated.
    As an example, there are steroids which, according to common opinion and some reviews, cause “roid rage” and unbridled aggression. This is, of course, complete nonsense. Even Trenbolone, in which such a tendency occurs, rarely increases the aggression enough to make it difficult to control. When using Trenbolone, it is much easier to get us off balance or annoyed by minor things, but it is certainly not a massive change – it is somewhat similar to having a bad day. Personally, none of my friends or my wife have ever complained about any change in my behavior even during several times higher doses of steroids than during typical cycles.
    For this reason, I believe that such reviews should be taken with a pinch of salt. Just a little self-control is enough to avoid noticeable differences in behavior. 

Does S23 require PCT?


While most SARMs do not affect HPTA, in the case of S23, the situation is different. Unfortunately, in most cases, the S23 cycle requires PCT. 

Of course, PCT is by no means scary, as many people imagine it. It basically involves taking SERMs over a period of about a month. These drugs stimulate the pituitary gland, increasing the production of LH and FSH, and thus indirectly testosterone and other hormones. 

The most commonly used SERMs for PCT are Clomid and Nolvadex. Personally, I prefer the latter because Clomid may cause estrogenic side effects in some people. 

Nolvadex should be used for PCT purposes for about 4 weeks after the discontinuation of S23 in a dose of 20 mg per day.

You can buy pharma-grade Novalex here (they do not send to North America).

If you live in North America, you can buy Nolvadex from SwissChems. 


The doses used in the studies range from 0.5mg to 50mg. 

However, most bodybuilders decide to use 20 or 30 mg daily. 

S23 is quite a strong agent. Personally, I would suggest to start rather slowly and not exceed 20mg per day.

The half-life time is about 12 hours. This means that the daily portion should be divided in half in order to maintain a stable concentration of the substance in the blood.

S23 is often combined with other SARMs. Personally, I think it’s a much better idea than a reckless dose increase. An example of a cycle with S23:

LGD-40335mgWeek 3-8
MK-286630mgWeek 1-8
S2310mgWeek 1-8

S23 before and after

Where to buy S23?

Unfortunately, most of the products advertised as SARMs have little to do with what’s on the label. A large number of products on the market instead of SARMs actually contain steroids or prohormones. An equally common case is the smaller amount of agent in relation to the label, caused by the high price of SARMs in wholesale. For this reason, SARMs should only be purchased from reliable sources that have a certificate of analysis for each product offered, issued by an external laboratory.

Recommended vendors:

chemyo logo

One of the most popular SARM stores in the world. In recent months it has been gaining popularity, especially among Reddit users. The offer includes SARMs only in the form of solutions. Unfortunately, the bottle does not come with a pipette. You have to buy a syringe yourself (they are available in their shop) or another device for measuring liquids. They are the only ones to publish a certificate of analysis for each product directly on their website. There is also a contact phone on the website, so you can usually get answers to any questions within a few minutes. Shipping from the USA.
Link to their website

swisschems logo

Relatively new store. It is not very popular at the moment. It is most likely caused by the fairly high prices of offered products. The offer includes SARMs in form of capsules and injections. Apart from SARMs, they also sell PCTs, peptides, and drugs for erection problems. For each product, you can receive a certificate of analysis by e-mail. Shipping from the USA.
Link to their website


Although it has been our favourite shop for a long time, we are forced to change our recommendation. In recent months, contact with them has become difficult, parcels are delayed, and there is a lot of negative feedback on the effectiveness of their products. I apologize to all the people who bought their products in recent months based on my recommendation.

Frequently Asked Questions

Does S23 cause hair loss?

We currently have too little data to determine whether S23 can cause hair loss. None of the studies conducted so far have indicated that it could have any effect. However, I have encountered a few reviews in which users of this product have claimed that it causes hair loss. 

If you have a problem with MPB, I would advise you to try first the products that are considered completely safe for your hair or to include finasteride/ RU58841.

Do I need PCT after cycle? 

It depends on a number of factors, including the length of the cycle and the doses used. Personally, I would suggest using PCT as a preventive measure. PCTs drugs have no additional side effects and will help you to get back to normal much faster and maintain more muscle gained during the cycle. 

Is S23 legal?

At the time of writing this article, S23 is legal in the USA and in most countries of the world. However, the substance is included in the WADA list, so it cannot be used by athletes taking part in competitions.