Ostarine (Enobosarm, MK-2866): Uses, Side Effects & Dangers

Substance Profile: What Athletes Need to Know about Ostarine

Ostarine (Enobosarm, MK-2866): Uses, Side Effects & Dangers

To take part in elite competitions, many athletes must comply with the World Anti-Doping Agency Prohibited List, a strict global standard that prohibits the use of certain substances and methods because of their potential to enhance performance and cause negative health effects. The WADA Prohibited List is an internationally recognized standard, with more than 660 signatories, that helps ensure that athletes can compete on a level playing field around the world.

Among its various Prohibited List resources for athletes and their support personnel, USADA publishes substance profiles to highlight vital information about high-risk substances, including ostarine.

What is ostarine?

Ostarine is the trademarked name for a Selective Androgen Receptor Modulator (SARM) that is not approved for human use or consumption in the U.S., or in any other country. In recent years, WADA has reported an increasing number of positive tests involving SARMs, and athletes who use these substances most ly obtain them through black market channels.

Research has shown that SARMs ostarine have fewer androgenic properties, meaning they have less influence on the development and balance of male hormones, including testosterone.

While they are not yet approved for human use, SARMs are of interest to the medical community because they might be effective at treating different health conditions without resulting in the negative side effects of steroids.

Ostarine is currently being investigated as a way to treat a variety of muscle wasting diseases, such as osteoporosis, cancer, and hypogonadism.

Is ostarine prohibited in sport?

Yes, ostarine isprohibited at all times under the S1 Anabolic Agent category of the WADA Prohibited List. The number of positive tests involving ostarine has increased steadily over the past few years, with WADA reporting 28 globally in 2015.

Do everyday products contain ostarine?

There are in fact products that contain ostarine, but only illegal ones. Given that ostarine is not approved for human use or consumption in the U.S., or in any other country, there are no legal medications that contain ostarine.

It’s also important to note that ostarine is not a permitted ingredient in dietary supplements. However, you should be aware that some dietary supplement manufacturers illegally put SARMs ostarine in their products and sell them as “legal steroids” or “research only” chemicals.

Moreover, they may omit ostarine from the label entirely, or use misleading names to confuse consumers. For example, ostarine may also be called enobosarm, MK-2866, or GTx-024. Some examples of supplements that contain ostarine can be found on the USADA High Risk List.

Click here for an advisory on ostarine in supplements.

What are the health risks associated with ostarine?

Because ostarine is still being investigated for use in humans, the side effects have not been fully characterized yet. For recent information on the effects of ostarine, take a look at this 2013 study from the National Center for Biotechnology Information.

What if I need to use ostarine as part of a medical treatment?

Keep in mind that ostarine is not currently available as a prescription medication in any country. No matter what medical condition you have, your doctor is not legally allowed to prescribe ostarine to you as a treatment.

More reading on SARMS and ostarine:



Need more information?

Research your medications on GlobalDRO.com.

Learn about supplement risks on Supplement411.org.

Contact Athlete Express with questions.

Source: https://www.usada.org/spirit-of-sport/education/substance-profile-ostarine/

Ostarine: Understanding the drug that might get Taylor Lewan suspended

Ostarine (Enobosarm, MK-2866): Uses, Side Effects & Dangers

Tennessee Titans left tackle Taylor Lewan released an emotional video on social media Wednesday informing the public that he had unknowingly taken an NFL banned substance. In his video, Lewan references the drug ‘ostarine’ as the substance that he failed him the drug test. Ostarine shows up on the NFL Player Association banned substance list.

From the USDA.org website, here’s a breakdown of what the drug exactly is.

OSTARINE: Uses, Side Effects, Interactions and Warnings

Ostarine (Enobosarm, MK-2866): Uses, Side Effects & Dangers
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2017-18 NCAA Banned Drugs List. National Collegiate Athletic Association (NCAA), June 5, 2017. http://www.ncaa.org/2017-18-ncaa-banned-drugs-list. Accessed: Sept 7, 2017

Coss CC, Jones A, Dalton JT. Pharmacokinetic drug interactions of the selective androgen receptor modulator GTx-024 (enobosarm) with itraconazole, rifampin, probenecid, celecoxib and rosuvastatin. Invest New Drugs 2016;34(4):458-67. View abstract.

Dalton JT, Barnette KG, Bohl CE, et al. The selective androgen receptor modulator GTx-024 (enobosarm) improves lean body mass and physical function in healthy elderly men and postmenopausal women: results of a double-blind, placebo-controlled phase II trial. J Cachexia Sarcopenia Muscle 2011;2(3):153-61. View abstract.

Dart DA, Kandil S, Tommasini-Ghelfi S, et al. Novel trifluoromethylated enobosarm analogues with potent antiandrogenic activity in vitro and tissue selectivity in vivo. Mol Cancer Ther 2018;17(9):1846-58. View abstract.

Dobs AS, Boccia RV, Croot CC, et al. Effects of enobosarm on muscle wasting and physical function in patients with cancer: a double-blind, randomised controlled phase 2 trial. Lancet Oncol 2013;14(4):335-45. View abstract.

Dubois V, Simitsidellis I, Laurent MR, et al. Enobosarm (GTx-024) modulates adult skeletal muscle mass independently of the androgen receptor in the satellite cell lineage. Endocrinology 2015;156(12):4522-33. View abstract.

Dynamic Technical Formulations, LLC. Issues a Voluntary Nationwide Recall of Tri-Ton Due to the Presence of Andarine and Ostarine. FDA Recalls, Market Withdrawals, & Safety Alerts, May 19, 2017. https://www.fda.gov/Safety/Recalls/ucm559700.htm?source=govdelivery&utm_medium=email&utm_source=govdelivery. Accessed: Sept 7, 2017.

FDA. FDA Warns against using SARMs in body building products. October 2017. Available at: https://www.fda.gov/newsevents/newsroom/fdainbrief/ucm583021.htm.

Selective Androgen Receptor Modulators (SARMs) – A Prohibited Class of Anabolic Agents. U.S. Anti-Doping Agency, November 18, 2015. https://www.usada.org/selective-androgen-receptor-modulators-sarms-prohibited-class-anabolic-agencts/. Accessed: August 30, 2017.

Thevis M, Geyer H, Thomas A, Schänzer W. Trafficking of drug candidates relevant for sports drug testing: detection of non-approved therapeutics categorized as anabolic and gene doping agents in products distributed via the Internet. Drug Test Anal 2011;3(5):331-6. View abstract.

USADA. Athlete Advisory: Ostarine in Supplements. July 2017. Available at: https://www.usada.org/growing-evidence-ostarine-athlete-risk/.

Van Wagoner RM, Eichner A, Bhasin S, Deuster PA, Eichner D. Chemical composition and labeling of substances marketed as selective androgen receptor modulators and sold via the internet. JAMA 2017;318(20):2004-10. View abstract.

WADA. What is prohibited. 2019 list of prohibited substances and methods. Available at: https://www.wada-ama.org/en/content/what-is-prohibited/.

Source: https://www.webmd.com/vitamins-supplements/ingredientmono-1564-ostarine.aspx?activeIngredientId=1564&activeIngredientName=ostarine

5 Benefits Of Ostarine (MK-2866) for the Muscles

Ostarine (Enobosarm, MK-2866): Uses, Side Effects & Dangers

What is Ostarine and can it really help bodybuilders build a wider physique, sculpt lean muscles, drop body fat, and increase muscle strength? Find out the answers here!

RELATED: What Is Androstenedione And Why Should You Take It?

In this article:

An Overview of Ostarine (MK-2866)

Ostarine is a selective androgen receptor modulator or SARM medical professionals use to prevent muscle loss in specific patients. Researchers conduct clinical trials on the effects of these SARMs in patients suffering from prostate cancer and lung cancer, among others.

Meanwhile, some bodybuilders take SARMs supplement with Ostarine to build lean muscle mass, increase muscle strength, and speed up fat loss. While taking SARM drugs and pills have become popular, bodybuilders should first assess its effects, possible health risks, and proper dosage.

What Is Ostarine?

Product: MK-2866 OstarineSynonms: Enobosarm, MK-2866,GTx-024, 1202044-20-9,anabolic SARMSpecification: 99%Mesh size: 80 MeshCAS: 841205-47-8MF : C19H14F3N3O3MW : 389.33 g/molPurity: 99.0%

Appearance: White Powderhttps://t.co/StGgNxBU8x pic..com/yu06B2YHs9

— kitty Li (@kittyLi93303528) January 14, 2019

Ostarine is a SARM with very similar effects on the body as anabolic steroids. In fact, steroids, these compounds also stick to the androgen receptor found in the skeletal muscle system.

What differentiates Ostarine from anabolic steroids is SARMs only target a specific receptor in every muscle or bone. As such, users might not experience complications suppressed testosterone levels, liver damage, or androgenic effects.

Androgenic Effects Definition: The development of secondary male characteristics as a result of imbalanced hormone levels. This may include acne, facial hair growth, and male pattern baldness.

Since SARMs Ostarine seem to pose fewer health risks, some bodybuilders use it to replace anabolic steroids. They claim it can help one safely increase lean muscle mass, build muscle strength, and reduce body fat levels.

While it is safer as compared to anabolic steroids, gym-goers should remember SARMs weren’t meant for bodybuilding. Their main purpose is to prevent muscular dystrophy (weakening of skeletal muscles) among STD and cancer patients.

Also, the World Anti-Doping Agency prohibits the use of these SARMs. As such, athletes won’t be able to enter most major sporting competitions if they’re under the influence of SARMs.


  • Can increase lean muscle mass
  • Improve overall strength and performance
  • Can possibly increase insulin resistance


  • Illegal to take without a medical prescription
  • No country approves the use of Ostarine
  • Lack of clinical studies on long-term risks

How Does Ostarine Work?

Androgens help the body build muscle gains. That’s primarily the reason why men can sculpt lean muscle gains faster than most women can.

While taking SARMs Ostarine might improve one’s physique, it also has a number of side effects. It’s no different from taking prohormones or following steroid cycles, bodybuilders are still at risk.

Of course, that doesn’t change the fact that it’s still a bit safer than anabolic steroids.

For example, while SARMs target androgen receptors, they do not affect reproductive organs that steroids usually damage. Its muscle-selective properties are what makes it appealing to bodybuilders.

1. Build Muscle Mass

A clinical study on 120 healthy aged humans suggests Ostarine not only prevents muscular dystrophy, but it also stimulates muscle growth. Subjects who took a daily dose of 3 mg showed good results, while those who took a lower dose did not progress as much.

2. Better Bone Health

Apart from bone mineralization, patients with weak bones can strengthen their skeletal system by packing on muscle mass. A larger, well-built frame can prevent bone fractures and speed up recovery.

Also, clinical trials on animals prove Ostarine really does have the potential to improve both bone and muscle strength. Just keep in mind that no studies can confirm the effects of SARMs on human bones.

3. Heart Health

Apart from preventing weight and muscle loss, Ostarine SARMs may also help with improving one’s heart health. A study on 120 healthy elderly men shows a daily dose of 1 mg to 3 mg of Ostarine may lower lipids such as HDL cholesterol and triglycerides.

4. Insulin Resistance

In the same study on 120 healthy, elderly men, researchers found that Ostarine may improve insulin resistance and lower blood glucose content. The studies showed the SARMs had the same beneficial effects as anti-diabetic medication such as Metformin.

5. Muscle Stem Cell Activation

Stem cells regenerate and restore different muscles in the body. Similarly, some studies suggest Ostarine can stimulate stem cells in the connective tissue to speed up muscle recovery.

Advanced Research on SARMs Ostarine

  • Bioavailability: A study on male and female rats showed the body absorbs and transports these SARMs quickly and efficiently throughout the body.
  • Dosage: 1 mg of Ostarine a day may increase one’s total lean muscle mass. Meanwhile, taking 3 mg per day will only increase the muscle mass by two pounds.
  • Disease-Prevention: Clinical trials on Ostarine are currently underway to see its effects in preventing breast cancer, low testosterone complications, muscle atrophy, muscular dystrophy, and incontinence.

RELATED: 7 Testosterone Supplements Side Effects To Expect

Ostarine Review

Ostarine has always been used for muscle atrophy treatments among patients suffering from diseases cancer and STD. As such, there’s not much research on its effects on fitness and dieting.

Some bodybuilders who want to take a break from their steroid cycle use SARMs Ostarine instead.

They claim it offers the same benefits as anabolic steroids but without the possible adverse effects, although a few reports state the muscle-building effects of Ostarine aren’t at par with the effects of anabolic steroids.

Meanwhile, some users simply take Ostarine for their post-cycle therapy after their steroid cycle.

Ostarine for Bulking

Men: 25 mg daily

Women: 10 mg daily

Ostarine is ideal for bulking. Here are its effects:

  • Lean, shredded muscle gains
  • No water retention
  • Improved protein synthesis and anabolic activity
  • Increased endurance
  • Higher energy levels
  • No “roid rage”

Ostarine for Cutting

Men: 20 mg daily

Women: 10 mg daily

Ostarine may not speed up fat loss as much as it can build muscle, but it can prevent muscle loss. Here are its effects:

  • Retaining muscle mass
  • Maintaining muscle strength even on a low-calorie diet
  • Slight fat loss

Body Recomposition

Men: 12 mg to 25 mg daily

Women: 12 mg to 25 mg daily

Body recomposition is the process of adding muscle mass while simultaneously losing fat. It’s usually impossible without the help of performance-enhancing drugs. Here are its effects:

  • Weight gain
  • Sculpting lean muscles
  • Retaining energy levels

Muscle Recovery

Ostarine may be used as a supplement for muscle recovery because it has the following effects:

  • Faster muscle recovery (at a dosage)
  • Flexible joint mobility
  • Speeds up the healing of tendon and bone injuries

Ostarine Side Effects, Warnings, and Cycling

Fitness buffs shouldn’t take Ostarine for more than 12 weeks. Also, they should immediately take a post-cycle therapy program lasting for four weeks during their 12-week break.

Here are some of the nasty side effects of Ostarine:

  • Testicular pain
  • Strength reduction
  • Insomnia
  • Low energy levels
  • Erectile dysfunction
  • Nausea
  • Male pattern baldness
  • Headaches
  • Acne
  • Gynecomastia
  • Increased hunger

Is Ostarine a Good Steroid Alternative?

Should gym-goers buy Ostarine and use it as an alternative to steroids? The answer is no because it’s not that much safer than anabolic steroids.

In fact, they’re both illegal and pose possible health risks. The only difference is the way they attach to the androgen receptor in the skeletal muscle system.

For a safe, all-natural alternative, gym-goers should use legal steroids! These are 100% safe and legal supplements that imitate the effects of steroids without the harmful health risks.

Gym-goers can try the bulking stack, strength stack, or cutting stack as well. Choose the one that best suits one’s goals, needs, and lifestyle.

This video from Iron Jaguar talks about the results and sides effects of Ostarine (MK-2866):

Overall, Ostarine is a selective androgen receptor modulator (SARM) drug that can prevent muscular dystrophy and muscle loss. Researchers use it to study its effects on sick patients but not on healthy bodybuilders.

Also, the use of this is prohibited and may get one banned from entering most major sporting events. As such, gym-goers should try other supplement options that will align with their goals.

Have you ever tried Ostarine? Do you have more questions about it? Share your thoughts in the comments section below!

Up Next:

Anthony Thomas is a personal trainer and health coach with over 20 years of experience. After tearing his ACL in high school football, Anthony shifted his attention off the field where he could focus on healing and getting stronger. This is where he found his love for bodybuilding, as he found himself getting stronger and stronger with the right diet, supplements, and workout routine.

After studying physical training he found a love for people and how to help them heal, get strong and fit, and have fun while doing it.

Anthony now spends his time with a few private clients, but mostly online devoting his time and attention to AskMuscle.com where he can share his knowledge with readers around the world.

Aside from working out, Anthony enjoys a quiet and simple life and the occasional fishing trip with Sam, his German Shepard.

Source: https://askmuscle.com/ostarine-benefits/

Ostarine (MK-2866)

Ostarine (Enobosarm, MK-2866): Uses, Side Effects & Dangers

Hey there wannabe juicers. Since you are reading this Ostarine (MK-2866) review, we figure that you are veering towards your maiden PED cycle.

But you are on the fence about hopping on toreal gear.

We don’t blame ya. Gear isn’t for everyone.

Definitely not for someone who isn’t preparedto accept it as a lifestyle. Because after that first cycle, chances are thatyou will keep yearning for more.

The next best thing that your research throws up is SARMS.

But again, the conundrum is whether theseresearch chemicals are really as mild as they are touted to be.

You don’t want to end up with a neat pair oftits after a few weeks with your maiden SARMS cycle, do you?

That’s why we recommend Ostarine to anyonewho’s looking to dabble in PEDs.

Here are 9 traits of Osta that make it theperfect 1st-cycle compound for rank newbies.

#1 – Least suppressive among all SARMS

Ostarine, also called Enobosarm is one of theleast suppressive SARMS available currently.

So, even at performance enhancement doses,which usually ranges from 15-25mg/day, the chances of a complete shutdown ofyour endogenous testosterone production is close to zilch.

It may not even suppress you by 50% at those doses, which is very ly with stronger SARMS LGD-4033.

There are two ways to go about this. You can either start with the least suppressive SARM at a reasonable dose and see how your body responds to it.

Or, you can start with a high dose of thestrongest compound and put those virgin receptors to good use. Prudence andexperience suggests that the first method will yield better results whileminimizing the risk of side effects.

#2 – Ostarine helps maintain lean muscle during a cut

Ostarine is usually used by athletes andrecreational users to prevent muscle loss during an aggressive cut.

And it is very effective at this. Even if you are eating in a calorie deficit, you might still gain up to 2-4 lbs. of lean mass.

More importantly, you will not lose any musclemass, which is close to impossible on aggressive cutting cycles.

So, even if you have not perfected your diet,which a lot of newcomers are guilty of, you can still end up making decentgains with Ostarine. Whereas if you were to opt for a stronger compound, youmay end up gaining a boatload of water, particularly if you don’t have yourdiet dialed down to perfection.

#3 – Ostarine helps build muscle during a surplus

Enobosarm showed a dose dependent increase inlean body mass in a group of healthy, elderly men and women according to a clinicalstudy conducted in Sep 2011.

No adverse effects were noted.

In fact, the results were compared with the anabolic effects of testosterone without the stress on the prostate and the androgenic side effects of test.

This means that if you exercise, eat in asurplus, then you can use Ostarine to bulk up as well. So, if you have heard orread that Osta is only effective in a cut, then that’s BS.

It will still bind to your androgen receptorsand signal it to make more muscle. The amount of muscle you gain will depend onyour dinner plate.

#4 – Moderate strength gains


Ostarine gives you a nice strength boost. Butit’s moderate at best. Just the way it should be for a first cycle.

Nothing crazy that can make you go overboardresulting in an injury.

But with consistent training, you can easilysurpass your best lifts by week 5 or 6 of your cycle.

#5 – Effective even at low doses

Just LGD-4033, Ostarine is surprisingly effective even at low doses. In the clinical trial that we mentioned above, volunteers gained an average of 3 lbs. of lean muscle mass at just 3mg/day.

Most users looking for performance enhancementwill use at least 15mg/day if not more. Most people do 25mg/day.

With a dose dependent curve and increase inlean muscle mass, you can make significant gains with your first Ostarinecycle, even if you were to dose low.

#6 – Well tolerated at higher doses

anecdotal reviews, even doses as highas 30mg/day are tolerated exceptionally well in healthy men.

There are no adverse effects other thansuppression of endogenous testosterone.

So, if you have completed a first cycle with10mg/day, you can take a break for a couple of months and do a second cycle at20mg/day without the risk of too many side effects.

#7 – Keepable gains

None of the clinical trials have reported serious adverse effects with Ostarine.

Even anecdotal reports suggest that it might bethe safest of all SARMS being sold online currently.

There is no testicular pain, no hot flashes, noheadaches, joint aches or insomnia, all of which are reported with other SARMS.

You won’t look a bloated mess either. Thegains are dry, lean and you can easily maintain it even after you come off thedrug.

#8 – The only SARM to make it to Phase III of human trials

As of now, Ostarine is one of the only SARMS tomake it to Phase III of human clinical trials without being dropped midway orwithout being discontinued due to serious risks.

In fact, even when it failed the endpoint for Urinary stress incontinence in women, GTX is actively pursuing the drug in Europe.

All other SARMS have either been tested in-vivoor on lab rats.

#9 – Ostarine has Less chances of being laced with prohormones

Since most people go into an Ostarine cycleexpecting slow and steady gains, manufacturers don’t see a reason to spike itwith prohormones or oral steroids.

There is a risk of that happening with stronger compounds LGD-4033, RAD140 and YK-11, where people expect dramatic transformations overnight.

Closing thoughts

Don’t get caught up in the LGD vs. Osta vs. Raddebates on messaging boards.

Try Ostarine for your first SARMS cycle and we are sure that you won’t be disappointed with it.

Source: https://www.sharonhospital.com/ostarine-mk-2866-review/