Andarine vs Ostarine: Main Differences Compared

Selective androgen receptor modulators or SARMs are gray market research chemicals that are popular among bodybuilding and fitness buffs. While healthcare professionals and regulatory bodies like the World Anti-Doping Agency (WADA) and the US Food and Drug Administration (USFDA) have banned them for their harmful properties, their popularity seems unfazed.

They are similar to steroids but are said to be safer. SARMs are also said to keep their business only to muscles and bones, unlike steroids which mess with your reproductive organs. None of them are approved for human consumption anywhere in the world. But they are available in the black market. We will touch upon the how and why of that in a minute.

This article will compare the biggest differences between Andarine (also known as S4), and Ostarine (or MK 2866).

Common Usage:Cutting/RecompCutting
Side Effects:HighMinimal
Safe For Women:Not RecommdedYes
Average Dosage:50mg/day25mg/day
PCT Recommended:YesNo
Anabolic Ratio:Unknown10:1

Andarine is great with the androgen receptors of the human body and is known to mimic the effects of testosterone. It has a stronger impact on muscles and bones than reproductive organs which is why proponents of SARMs argue that it is safer than steroids. But some users have reported having experienced testosterone suppression. This can be treated with post-cycle therapy.

Ostarine or enobosarm or MK 2866 is another SARM that is known to stimulate steroid hormone receptors and also has similar effects on the body. Many users of ostarine have said that it is a safe option for those who want to gain muscle mass and enhance performance with fewer side effects compared to steroids. This is one of the reasons sportspersons prefer it despite the WADA ban. It features under the S1 Anabolic Agent category of the Prohibited List. 

The Main Differences between Andarine vs Ostarine

Main Differences

Andarine and ostarine are being researched for similar things but there are a few differences.

  • Ostarine is virtually side effect free, Andarine is known to have vision related side effects.
  • Ostarine is mainly used for fat burning and body recomposition, whereas andarine cycles are good for preserving muscle mass.
  • Ostarine is also good with recovery in case there is an injury, whereas andarine focuses entirely on adding muscle mass.
  • Ostarine has fewer side effects when compared to andarine.

Background of SARMs such as S4 and MK 2866


SARMs are largely sold and bought by many supplement companies on the internet and otherwise too. This is particularly true in the US. 

However, today they are predominantly black market products that are not cleared for human trials or human consumption. Sarms like Ostarine and Andarine are fan favorites in the bodybuilding community because of the lack of side effects experienced through traditional steroids.

So, researchers continue to show interest and so SARMs are available in the market as a research product. Since there is a lot of interest in the bodybuilding community, many distributors sell them under the radar. 

This has also led to many watered-down and bunk products flooding the market. So those who want to try SARMs must make sure that they are procuring high-quality substances. You can find some of them here.

One of the oft-asked questions about SARMs is how they are different from steroids. SARMs have the ability to stimulate bone and muscle growth with fewer prostatic effects in men and virilizing effects in women. 

They have brought back the almost dead search for improved androgens.

Steroids, on the other hand, are known to increase the development of muscles but also come with a ton of unwanted side effects, especially on reproductive organs. This leads to things like acne, breast development in men, enlarged prostate and shrinking of the testicles.

In women, it leads to excess growth of hair, acne and an increase in the size of the clitoris. In fact, steroids are also known to cause liver damage, heart issues and an increase in the risk of blood clots. None of these issues are present when using either Ostarine or Andarine.

What does it feel like to be on Andarine?


As mentioned before, andarine is a strong SARM and helps preserve muscle mass and build lean muscle. There is no established dosage for andarine but then again, there isn’t any scientific way to try any SARM. So, let’s go by general consensus.

Many users have reported that 15 mg per day for eight weeks is a good start. Do remember that you can take a lot more than that if you have done this before. But with an increase in dosage, there is an increase in the risk of side effects.

The potential side effects of using andarine are testosterone suppression, trouble seeing at night, mild liver toxicity, decreased HDL cholesterol and slightly accelerated hair loss.

Ideally, beginners should do 15 mg per day and experienced users can go for 25-50 mg per day. Andarine has a half-life of four hours. So, you should split higher dosages and take it through the day.

Users who have done this before like to stack their SARMs. This means they like to take more than one SARM to get different benefits from different substances. If that is your style, here’s a little guide.

Andarine is best for cutting cycles and can be combined with cardarine or ostarine. You can go for 50 mg of andarine, 20 mg of cardarine and 25 mg of ostarine per day during the cutting cycle.

But if you want to try it during the bulking cycle as well, you can combine it with Ligandrol or YK11. Take 25 mg of andarine, 20 mg of Ligandrol and 10 mg of YK11 per day during the bulking cycle. Remember that andarine and Ligandrol are both strong SARMs.

What does it feel like to use Ostarine?


Those who are taking ostarine for bodybuilding purposes should start with 15 mg per day. This is a good dosage for rapid results and works well for a cycle of eight weeks. Experienced users can go up to 20 mg per day. You could also push your cycle to 12 weeks but if you extend the cycle, the results will plateau.

Ostarine cycles work best with an increase in protein consumption. Some users say post-cycle therapy is a good move after an ostarine cycle while some others say it is completely unnecessary. The best way to determine that is to get a blood test done before starting the cycle and checking the levels again when the cycle ends.

A typical ostarine cycle involves 15 mg of ostarine per day for eight weeks. Post-cycle therapy goes on from week 9 to week 12. Weeks 12 to 16 are all about resting and allowing your body to come back to equilibrium. You can stack it with 15 mg of Ligandrol and 25 mg of Ibutamoren during the bulking cycle if you are an experienced user. During the cutting cycle, try 10 mg of cardarine per day and 50 mg of andarine.

The common side effects of ostarine include decreased HDL levels, back acne, joint pains and an increase in hunger. You should start another SARM cycle only after a four-week break and can choose to extend it should your body need it.

Final Verdict: Which SARM is better?


Both andarine and ostarine are made by the same company with the same goal. One of the biggest differences between the two is that one is stronger than the other. Ostarine works well during the cutting cycles and andarine is good with preserving muscle mass.

There are many blogs and websites on the internet that actively promote a high dose of andarine. One can only hope that your research goes beyond that so that you know better than to do that.

There is a certain amount of risk you take when you try products that are not cleared for human consumption. All SARMs come under that category. And even though they are supposedly a better alternative for steroids, they come with plenty of risks on their own.

So if you do decide to take these substances, be sure to eat and train well depending on your dosage. Get a blood test done beforehand and monitor your progress on a daily basis. If anything seems out of the ordinary during the cycle, stop it right away.

Chris Jackson
Chris Jackson

Chris Jackson, co-founder of, is a renowned fitness blogger, physique model, and evolutionary bioscience researcher specializing in SARMs (Selective Androgen Receptor Modulators). His extensive work, characterized by cutting-edge research and practical training advice, has made a leading source for accurate, credible information on performance enhancers. With a dedication to improving the understanding and application of SARMs in optimizing human performance, his contributions have not only expanded public awareness but also shaped the conversation around these substances. Chris's pursuit of knowledge and commitment to sharing it continue to inspire many in their fitness journeys.

  1. Hi, can I stack ostarine with lgd 4033


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