Everything about Ostarine: results, side effects and dosage

What are the benefits of Ostarine? What dosage should I take? Does it have any side effects? We will answer these and many more questions in this article.

What is MK-2866 (Ostarine)?

Ostarine, also known as MK-2866 and Enobosarm, is one of the most well-studied and popular selective androgen receptor modulators (SARMs) on the market.

Since its discovery in the early 2000’s, GTx (which has been developing the SARM) has conducted over 8 clinical trials on MK-2866 involving over 600 subjects.

It is currently in phase 3 of human trials and has been shown to prevent bone loss and muscle wasting associated with certain conditions.

Ostarine’s ability to accelerate muscle growth, increase bone density, and improve recovery, have made it a highly popular compound among bodybuilders and athletes.

It is commonly recommended to first-time users because it is milder and has fewer side effects than other SARMs. If a woman were to consider taking SARMs, very low-dose ostarine would be the smartest option.

Ostarine is also known as MK-2866 or Enobosarm. It is a SARM which is short for Selective Androgen Receptor Modulator. It mimics the effects of testosterone, by binding to the androgen receptors in specific types of tissue.

What does Ostarine do to the body?

Ostarine acts as an agonist of the androgen receptor (AR), which is the biological target of androgens and anabolic steroids such as Testosterone. Androgen receptors can be found in tissues throughout the body. Selective Androgen Receptor Modulators (SARMs) are a class of drugs that selectively activate the androgen receptors in specific tissues, mainly skeletal muscle.

The primary benefit of Ostarine’s selectivity is that it provides many of the advantages of anabolic steroids while minimizing side effects. By activating androgen receptors in skeletal muscle, Ostarine promotes anabolic effects, which lead to increased lean muscle mass, improved bone density, and faster recovery.

Unlike anabolic steroids, MK-2866 does not undergo aromatization or 5-alpha-reduction, meaning it does not convert to estrogen or dihydrotestosterone (DHT), which are responsible for most of the steroid-related side effects Basaria et al., 2013.

What is MK-2866 used for?

Ostarine MK-2866 has been developed to prevent muscle loss and bone wasting in specific diseases.

These anabolic properties are exactly the reason why it has gained popularity among bodybuilders and athletes.

1. Building muscle/muscle growth – Ostarine can do a lot more than prevent muscle loss/muscular dystrophy. It can also help you to gain lean muscle mass and reduce body fat.
2. Lean muscle – When bodybuilding with MK-2866, you won’t experience the same amount of weight gain as with steroids. But you will gain strictly lean muscle mass, without the risk of water retention or gynaecomastia.
3. Muscle recovery – this is particularly important for workouts because the faster you recover; the quicker you’ll be able to get back into the gym.
4. Joints and tendons – its protective properties – namely its ability to guard your joints, tendons and bone tissues – have made this SARM particularly popular amongst athletes.
5. Bone health – the loss of bone-protective sex hormones as we age can result in poor bone health and even osteoporosis. Increasing muscle mass can help to reduce the risk of bone fractures and ensure a speedy recovery.

Ostarine helps by mimicking testosterone in your muscles and bones, providing support to your skeletal system and in the healing of fractures. It is also beneficial in the prevention of bone diseases.

Ostarine MK 2866 benefits & side effects

SARMs are considered to be milder than anabolic steroids, both in positive and negative effects. This means that the benefits (such as muscle gain rate) will be less pronounced, but so will the side effects.

MK-2866 is by far the best-researched SARM currently on the market. It is also the mildest and safest one. While most users experience little to no side effects, studies have shown that there are certainly risks when taken at high doses or for an extended period.

Ostarine benefits

Ostarine is developed to imitate the effects of anabolic steroids, but without the adverse side effects. It was originally designed to help people with muscle-wasting diseases such as osteoporosis, as it binds to the androgen receptors.

It did not take long for athletes and other gym fanatics to discover the benefits, and it is currently the most popular SARM on the market.

The main benefits associated with the use of Ostarine are:

• Improvement in muscle mass
• Faster recovery between trainings
• Higher bone density
• Reduced risk of fractures and injuries
• Maintaining muscle mass during a caloric deficit

Improvement in muscle mass

Multiple studies have shown that MK 2866 can increase lean muscle mass at dosages as low as 1mg per day. A recent study from 2020 showed that both MK-2866 and LGD-4033 had shown positive effects of lean muscle mass.

When used during a caloric deficit, it helps to maintain muscle mass.

Improve strength and performance

Next to gaining muscle, most studies showed an improvement in physical performance as well.

Most users who took this SARM for a cycle of 8-12 weeks noticed an increase in strength and also improved performance while working out.

Higher bone density

Ostarine has been developed for the treatment of osteoporosis and other diseases that cause bone mass loss. MK-2866 is praised because it prevents bone loss by increasing the density of bone minerals.

Ostarine side effects and risks

Research and anecdotal reports have both shown that MK-2866 usually doesn’t cause any adverse side effects.

However, some studies suggest that taking Ostarine for a longer period of time could lead to serious health problems.

Reported side-effects associated with the use of Ostarine include:

• Headache 
• Back Pain
• High Blood Pressure
• Suppress testosterone
• Liver Injury

Is Ostarine legal?

Ostarine’s legal status is similar to that of most other SARMs and related research chemicals. Because it has not been approved for human consumption by the FDA and EMA, it is illegal to sell it as a dietary supplement. Ostarine is also not currently available as a prescription medication in any country, so it can’t be prescribed by a medical professional for any form of treatment.

Ostarine, like most other SARMs, is considered doping by the WADA and USADA because of its performance-enhancing properties and therefore banned for use in any professional sport.

But because Ostarine is not a scheduled substance in most countries, it is also not downright illegal. This is why it is generally sold as a research chemical, which places it in a somewhat legal gray area. This makes the situation somewhat confusing, as it may be seized by customs in some countries but not in others.

Suppose you want to buy Ostarine online without worrying that it will be confiscated during shipment. In that case, it is essential to purchase it from a vendor that provides highly discreet packaging and shipping, such as HQSARMS. They provide guaranteed delivery for all products, giving you the peace of mind that your order will actually arrive without any issues.

Read all about the legality of SARMS in our blog post: Are SARMS legal in Europe?

Professional sports

It’s important to know, however, that Ostarine, as well as the other SARMs, are prohibited in competitive sports.

Ostarine is listed as a banned substance by almost all sports bodies including the Olympics as well as organisations such as:

• USADA (U.S Anti-Doping Agency)
• WADA (World Anti-Doping Agency)

This is because of the obvious unfair advantages this compound provides, such as increased strength, muscle, and endurance.

Does Ostarine lower testosterone?

Anecdotal evidence has shown that Ostarine lowers testosterone levels when used for an extended period of time in high dosages.

So yes, technically MK-2866 will cause some suppression. But the amount of suppression is very low, compared to more potent SARMs, such as RAD-140 and LGD-4033.

Remember to stick to normal dosages and cycle lengths to ensure minimal suppression.

When not exceeding the common dose, there is no need for any PCT when using Ostarine.

Ostarine dosage and cycle guidelines

During clinical trials, MK 2866 proved effective in dosages as low as 1 mg. However, the dosages used by bodybuilders and athletes are a lot higher, ranging from 5 to 30 mg per day.

Recommended Dosage for Muscle Growth (Bulking)

For those using Ostarine for bulking purposes and overall muscle growth, the standard dose is:

• 15 to 25 mg per day
• Cycle length of 6 to 8 weeks

This range helps maximize lean muscle gains while still minimizing the risk of side effects. 

Recommended Dosage for Cutting and Fat loss

When used during a caloric deficit for the purpose of maintaining existing muscle mass while burning fat, the standard dose is somewhat lower:

• 10 to 15 mg per day
• Cycle length of 6 to 8 weeks

This dose supports muscle retention, increased vascularity, and fat oxidation during a caloric deficit without significant suppression of natural testosterone levels.

For Injury Recovery or Muscle Preservation

For tissue healing, recovery support, or therapeutic applications such as muscle preservation in aging individuals or during rehabilitation phases, a dose of 5 to 10 mg per day is usually sufficient. At these dosages, the risks of side effects are generally very low to non-existent.

The most common cycle length for most SARMs, including Ostarine (MK-2866), is typically between 6 and 8 weeks. However, some users choose to extend their use of MK-2866 up to 12 weeks, as it is considered a relatively safe compound that does not produce severe side effects.

We will give an example of 2 possible Ostarine cycles:

CUTTING CYCLE

This is a great cutting cycle. Ostarine at this dosage is very safe and will allow you to keep on all of your muscle mass while you are cutting.

BULKING CYCLE

Ostarine at this dosage will be great for bulking. You will gain a lot of muscle mass and will most likely lose fat at the same time. Remember to eat at maintenance or a slight calorie surplus.

Half-life of Ostarine

The half-life of Ostarine is 24 hours, which means it is sufficient to take it in a single daily dose. It doesn’t really matter whether it is taken in the morning or evening, as long as you stick to 24-hour intervals and take it at the same time every day.

Some users prefer to split the dosage into two parts, taking half of the dose in the morning and half in the evening.

Stacking Ostarine for cutting

Since Ostarine is a mild compound, you can stack it with pretty much any SARM. A popular SARM stack for cutting purposes combines Ostarine with Cardarine.

For even better results, S4 (also known as Andarine) can be added. These three compounds have a synergistic effect, making them a popular combination for those trying to maintain muscle mass during a caloric deficit.