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Ostarine (MK 2866): Dosage, Results, Side Effects, and More

Ostarine, also known as MK 2866, is one of the most popular SARMs available. It has a very strong anabolic effect, and can be used for both bulking and cutting. Ostarine was created by GTx to treat muscle wasting disorders such as cachexia.

In this article, we are going to discuss benefits, side effects, dosages, cycle examples, before and after pictures, and more. By the end of this article, you will have everything you need to know about ostarine.

If you are still unsure about anything, feel free to write us in the comments section below and one of our team members will answer your question asap!

Benefits of Using MK 2866

There are countless benefits to using ostarine vs steroids or other SARMs. Here are some of them:

It’s Extremely Mild

Side effects are the worst part about using anabolics of any kind, including SARMs. Luckily for us, ostarine is extremely mild and well tolerated in most everyone who tries it. It is very uncommon to experience side effects while on cycle.


MK 2866 can be used to bulk, cut, or even recomp depending on your goals and diet. It can truly help all levels of athletes achieve their goals, and it’s a staple in any sort of sarms stack as well.

Safe for Women

Ostarine is safe for women since it is not androgenic in any way. In fact, it even out performs the popular steroid anavar when used by women.

Impressive Physique Changes

Some of the results you can achieve from running a cycle are nothing short of mind blowing. Most people will gain muscle while also losing fat. Read more about the results below.

Results of Using Ostarine

Combining ostarine with your training routine can deliver some pretty incredible results. The results that come with a cycle will help improve muscle development, speed up fat loss, and improve physique. Some of the results you can expect are:

Muscle Growth

It’s not a secret that SARMs can help you build large amounts of muscle. Ostarine is no different. During an 8 week cycle of Ostarine, you can expect to gain around 7-10lbs of pure muscle mass. Many studies show that even after subjects stopped taking ostarine, they continued to retain that muscle mass.

Fat Loss

Although ostarine is not a direct aide to thermogenesis, it does help promote fat oxidation in humans. Users who are in a caloric deficit will experience much better muscle retention compared to those who do not use ostarine. In addition, it has been proven that increasing muscle mass will increase TDEE (how many calories you need a day to stay the same weight). When you gain muscle, your body will naturally burn more fat as energy in order to keep that muscle.

Strength Gains

Ostarine especially shines when combined with strength training, and users consistently report strength gains similar to those found in anabolic steroids. In fact, it is not uncommon to add 30lbs or more to your one rep max for bench press or squats. For this reason, MK 2866 is a very popular choice with athletes who want to increase their performance on the field or court.

Ostarine Before and After Pictures

We’ve collected some pictures that show before and after ostarine results. As you can see from the pictures, ostarine is a very potent SARM that can give some impressive drops in body fat but also pack on some muscle as well.

before and after ostarine

before after ostarine results

Results like the ones above are not uncommon when using this compound. Of course, your mileage may vary depending on how well you keep your diet and routine in check. Make sure to keep your protein intake high and you’ll have no issues achieving your goals.

Side Effects and Safety

One of the main concerns people tend to have when adding any sort of performance enhancer to their lives is what type of side effects to expect. Luckily, ostarine has very little side effects to deal with. With that being said, there will always be some rare occasions of people experiencing side effects, and we wouldn’t be doing our jobs if we didn’t talk about them. Let’s take a look at some of the side effects you might experience with ostarine.


I’ve only seen this happen in one case, and it may not be due to using SARMs. This user reported feeling depressed around a week after starting ostarine. In our opinion, this could be caused by a slight dip in testosterone levels, or it could just be a placebo. Worth nothing, nonetheless.

Hair Loss

Something to note before we go into this side effect is that hair loss from sarms ONLY occurs in people who already have male pattern baldness. If your hairline is fine, this does not apply to you. This user on the AnabolicMinds forum reported hair shedding on ostarine, but also mentioned in a later post that it reversed after stopping use. We find is suspicious that it caused hair loss, since it is not androgenic and should not have that side effect at all. It is very possible that this user received a fake product (that contained prohormones) and that is what caused the shedding.


Some people with naturally low testosterone might experience some lethargy while on cycle. This is because ostarine will slightly suppress your body’s natural production of testosterone. The good news is that your body will naturally fix the imbalance within a month after you stop taking it. With that being said, if you have been diagnosed with low T you might want to consider getting on TRT prior to starting a cycle.

Best Ostarine Dosage

Depending on who you ask, you might find different answers for which dose of ostarine is best. In our experience, we recommend following a few simple ides when deciding how much ostarine to take:

  • Start low and work your way up. Do not go to a maximum dosage without first seeing how your body will react to it.
  • Increase dosage every few days. Listen to your body while increasing dosage in order to recognize side effects.
  • Cutting cycles generally require a smaller dose than bulking. This is because it takes a smaller dose to promote muscle retention than creating new muscle.

With those key points in mind, lets jump into the best dose for different types of cycles.

Bulking Dosage

Bulking on ostarine will require a slightly higher dosage than cutting, for the reasons outlined above. It simply takes more of a compound to create muscle than it does to retain it.

For those reasons, we recommend 30mg a day for anyone weighing over 185lbs. For those weighing less, you should give 20mg a day a try and see how you react.

Like we mentioned above, we always recommend starting with a lower dose and working up. If you plan on doing a 30mg a day dose, we recommend working up like this:

  • 10mg for week 1
  • 20mg for week 2
  • 30mg for week 3 and beyond

If you respond well, you can skip the ramp up period for the next time you cycle MK2866.

For bulking cycles, we recommend no longer than 12 weeks.

Cutting Dosage

Using ostarine for a cut will require a smaller dosage than using it for a bulk. This is because it doesn’t take nearly as much of the compound to retain muscle mass while you lose fat.

We recommend no more than 20mg a day while cutting.

Start at 10mg a day for your first week, and increase to 20mg for week two and beyond.

Cutting cycles on ostarine should not last any longer than 12 weeks in order to prevent suppression.

Half Life

The half life of ostarine is 24 hours. This means that you can dose once per day with no issues in peak blood plasma levels. We do recommend splitting doses between morning and night (or every 12 hours) in order to keep levels the most steady.

Some people also enjoy dosing pre-workout, however we have found that doing so provides only a negligible difference.

Liquids vs Capsules vs Powders

The best formulation you will find will be a liquid version. This is for a couple reasons:

  • Providing accurate doses in capsules/pills requires expensive equipment, which most sarms providers do not buy due to the nature of the industry.
  • Powders (assuming they are 100% pure) are very hard to dose accurately, and can be dangerous if you accidentally consume too much.
  • Capsules force you to take full days dose at once, so you can not split between AM and PM like you can with liquids.
  • Liquids store well, and can be taken sublingually to increase effects.

Ostarine for Sale

If you want to buy ostarine online, there are a few things you should know before you place an order. First of all, there are a ton of fakes out there. We have reviewed over 20 different sarm suppliers, and found than over 75% of them provided either fake or under dosed products.

One of the most common things we see are suppliers who ship out solutions that contain prohormones such as superdrol. These prohormones are dangerous, can cause side effects like gyno, and will shut you down hard. Do not gamble with what you put into your body.

One company that we can recommend is Proven Peptides. We have tested their products and they are one of the only ones who consistently came in at over 98% purity for every single product we tested. This remained true even for the more exotic compounds such as YK11.

Use During PCT

One of the more interesting ways to use this compound is to actually take it during your post cycle therapy. Since MK-2866 is so mild, it can in theory be used to retain muscle mass while coming off of other anabolics such as testosterone. If you plan on doing this, you must know two things:

  • It is unproven that it works, and could even make things worse
  • Only use low doses, something like 10mg a day max.

Depending on who you listen to, you will find mixed reviews on using it for this purpose.

Common Questions

Here are some of the more frequently asked questions we get about this SARM. If you happen to find anything that we missed, you can leave a comment below and we will respond within a few hours.

How to take ostarine liquid?

You can take the liquid by simply measuring out the correct dose with an oral syringe, and squirting it into your mouth. Rinse down with water. You may also take it sublingually (under the tongue) and let it sit there for 1 minute before swallowing. Ostarine liquid is NOT for injection. It is an oral solution.

When does it kick in?

We usually find that it kicks in within one week. You will continue to feel it get stronger and stronger over the course of a month or so. By 30 days into your cycle, you will be in full beast mode.

How suppressive is this SARM?

It is actually one of the least suppressive sarms in existence. Blood work consistently shows that any reduced levels of testosterone are reversed within a month or two. This is one of the reasons for it being so popular.

How long does it stay in your system?

For those who are drug tested, I would recommend staying away from ostarine. However, if you plan on taking it anyways, I would recommend a solid month to let it clear your system completely.

Do I need to do PCT after?

Usually not, depending on cycle length. If you plan on going the full 12 weeks, it might be a good idea to do 4 weeks of tamoxifen (Nolvadex) at 20mg for four weeks. You will not need anything stronger than that (stay away from Clomid).

What to stack with it?

A good option is always MK 677 to raise your HGH levels. You can also stack with S4 or even cardarine for an even more potent drying effect.

18 thoughts on “Ostarine (MK 2866): Dosage, Results, Side Effects, and More”

    • That depends on where you buy your Ostarine from. I know that proven peptides formulates theirs at 25mg per 1ml.

      Therefore, if you are using their formulation, you would need 0.4ml to equal 10mg.

      Last time I ordered from them they included a measuring pipette with the order, so it’s easy to measure.

  1. What do you recommend for a beginner who is 100 percent natty and never done steroid/sarms before.

    Been working out for 5 years have a good base with fat around the belly and thighs.


    • Ostarine or LGD4033 would be your best bets. If you want to lean up, I’d stack either one with Cardarine.

  2. Have you ever heard of bruising occurring while running Ostarine? I’ve run two cycles and during both at some decent sized bruises appeared on my triceps for one and on my forearm for the other, they were not a result of physical contact as far as I am aware.

  3. Can ostarine be absorbed through the skin if you don’t use it but are testing positive for it? Please email me. I am desperately trying to figure out why my son continues to test positive for this substance but has never used it? Could his body be making something similar to this and mimicking it on a test? Please I am desperately looking for answers.

    • I think the most likely scenario is that your son was using Ostarine. To answer your question, Ostarine has a molar mass of 389.33g/mol and anything under 500g/mol can be absorbed transdermally. With that being said it would be difficult to absorb enough to test positive by just coming in contact with it. The Ostarine would need to be applied via a carrier (Propelyne glycol, DMSO, etc) to effectively penetrate the skin.

  4. If i want to try a cycle on Ostarine let say 8 week and then I want to compete in Olympic lifting Nationals how long do i have to stop using it, in order to be negative on the test.

    • The rule of thumb is that 5 half lives will keep you in the clear. The half life of ostarine is roughly 24 hours, so that would be 5 days after your last dose. In an Olympic competition, they might be using more sensitive testing, so to be safe I’d give it at least 2 weeks.

  5. what about using the stack of Ostarine and MK677 do they clear up in 5 half lives also or they take more time to clear up in the system for purpose of testing

  6. When reading the answer to whether or not a PCT should be used after a cycle, it says usually not but for 12 weeks, yes. So what’s the cutoff length between a PCT being recommended or not needed? I am considering trying an 8 week cycle.

    • A PCT is never “necessary” per se. Even with heavy anabolic use, your body will always recover naturally via homeostasis. A proper post cycle therapy is useful to minimize the time it takes to kick start your HPTA system. Using a SERM like nolva, clomid, or torem are all popular options.

      It’s a fine line. Too much SERM: Improve recovery time, but with side effects. No SERM: longer recovery time but guaranteed no sides.

      The best way is just to use a small dose. For nolva, 10mg should be fine. Clomid is more than enough at 12.5mg. Many studies back this up and the only people who should be using 50mg+ are females who are trying to increase fertility.

      I will say that if you’re doing 8 weeks of nolva only you’re probably fine to skip the SERM. Bouncing back from Ostarine is super easy.

  7. I will start using the stack of MK-2866 and MK-677. 25ml per day on both during the morning time. I usually training 3 days a week and the off days of training should i using it or not?

    • Yes, you want to keep using it even on your days off. Steady levels of both in your system will do a lot of good for building muscle even when you are not training. Remember, you grow in between gym sessions, not during them!

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