Ostarine Side Effects: All of the Potential Short & Long Term Known Issues for this SARM in 2019

Ostarine, also known as MK-2866, is a popular SARM in bodybuilding circles due to its muscle building properties. It’s especially effective at assisting lean muscle growth and is a safer alternative compared to similar substances on the market.

Most people tend to associate Ostarine with S1, which is a weaker SARM compared to what’s available out there. Unlike S1, Ostarine is incredibly potent and it’s one of the best SARMs that you can use to gain lean muscle mass quickly.

a picture of a man preacher curling a v bar

But, like other SARMs out there, Ostarine is not perfect. Sometimes it comes with negative effects that can affect your quality of life but they differ according to the user.

The good news is that a number of studies have been conducted on this SARM which have helped us better understand how this drug works.

Read on to find out what we know about Ostarine side effects and what you can do about them.

Does This SARM Have Any Undesirable Effects?

Unlike most other SARMs, taking Ostarine doesn’t lead to any severe conditions. But, it does affect the body in a way that produces noticeable changes. For instance, it won’t increase your estrogen levels, which is a common side effect caused by steroids.

But it might put your hormones off balance, albeit slightly. However, studies suggest that Ostarine’s slight influence on estrogen is what’s responsible for its joint healing effects.

Experts recommend that Ostarine shouldn’t be paired with an anti-estrogen, as doing so may lead to a hormonal imbalance. It’s interesting to note that this SARM won’t change your androgen levels even though it works through androgen receptors.

You’ll be glad to know that this has no effect on the blood vessels, the heart or the liver, and it won’t affect your sexual organs and prostate either. Similarly, you won’t develop acne or suffer from hair loss when taking it.

With Ostarine, you don’t have to worry about your testosterone levels plummeting but it’s important to note that some users may experience mild testosterone suppression but this isn’t always the case. Plus, total testosterone suppression is virtually impossible.

Some of the reported negative effects include:

  • Testicle pain
  • Joint pain
  • Nausea
  • Baldness
  • Headaches
  • Menstrual cycle imbalances
  • Reduced strength
  • Failure to increase muscle mass and/or strength within five weeks
  • Low energy
  • Depression
  • A feeling of being unwell for the first nine days
  • Testosterone suppression after four weeks of discontinuing it
  • Disrupted sleep
  • Erection troubles
  • Higher doses may lead to acne and skin changes as well as increased estrogen levels

Another reported side effect is gyno flare ups but this one’s quite uncommon. It often leads to a sore and inflamed nipple on one or both sides.

There’s no telling what causes these effects because they differ in appearance and degree from one user to another. The theory is that it depends on whether or not the user combined the Ostarine with other drugs or steroids.

a man who has suffered Ostarine side effects doing ab exercises

To help minimize the occurrence of these negative effects, some bodybuilders start PCT straight after their Ostarine cycle. This helps mitigate undesirable effects associated with testosterone and estrogen specifically and involves taking anti-estrogens like Clomid and Nolvadex. The PCT usually lasts 3 to 4 weeks.

For those taking a higher dosage, it’s recommended to combine the SARM with aromatase inhibitors like Arimidex and Anastrozole. Both of them are great at transforming androgens to estrogens, which makes them an ideal solution for users who are sensitive to estrogen as well.

With regards to PCT, it seems there’s no one size fits all approach. Some people use it and some don’t.

A number of users make it a point to follow their Ostarine cycles with aromatase inhibitors and anti-estrogens, or even start their aromatase inhibitors mid-cycle to help reduce the occurrence of any negative effects.

Some users recommend combining PCT and aromatase inhibitors together with a course of D-Aspartic Acid to stimulate testosterone production.

Side Effects for Male Users

Some male users who have taken Ostarine in high dosages have reported the following:

  • Testosterone suppression
  • Reduced sexual performance
  • Erection difficulties
  • Reduced strength

It’s important to note here that these negative effects rarely occur and even then only when the SARM is taken in unusually high dosages. But, they can last for quite some time if they occur.

Female Side Effects

The following negative effects are quite common in female users who take high dosages of Ostarine over the long term:

  • Enlarged clitoris
  • Irregular menstrual cycle
  • Bad nausea

I hate to sound like a broken record here, but it’s important to note that these negative effects are limited to users who abuse the SARM in high dosages, which isn’t recommended in any case.

Does this SARM Cause Issues with Vision?

A number of users have reported experiencing problems with their vision while taking MK-2866. You’ll find that this is a common complaint in online forums where users gather to share their experiences with Ostarine and other SARMs.

Obviously, the last thing you want is to lose your vision for the sake of big muscles so we did some digging around to see what the scientific data says.

Apparently, this side effect didn’t happen in any of the clinical trials that were conducted. The only way this can be possible is if the users combined the Ostarine with S4 which is known to cause this side effect.

However, even then, the good news is that this side effect will wear off as soon as you stop using S4.

a man at the gym doing side dumbell raises


Ostarine is a fantastic performance enhancement SARM that works similarly to steroids but is not itself a steroid.

As long as you stick to the recommended doses you shouldn’t experience any major side effects.

While you won’t gain the same amount of weight as you would with steroids, using Ostarine will help you gain lean muscle mass. This is all without any added fat, water retention or hormonal problems.

Ostarine will also help you protect your joints and tendons from injury when training.

But, avoid overuse as this can cause joint pain during workouts, as well as other side effects as mentioned in this article.

To learn more about this popular SARM visit this page.

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