Overview Information

Ostarine is an investigational drug that has not yet been approved by the US Food and Drug Administration (FDA). It is part of a class of drugs called selective androgen receptor modulators (SARMs). Some supplement companies have included ostarine in products for bodybuilding. The FDA considers supplements containing ostarine to be illegal.

Ostarine is used by mouth to improve athletic performance and for involuntary weight loss in people who are very ill, also known as cachexia or wasting syndrome. But there is very little good scientific research to support these uses.

How does it work?

Ostarine attaches to proteins in the body known as androgen receptors. When ostarine binds to these receptors, it tells the muscles in the body to grow. Unlike some other chemicals that bind to androgen receptors, such as steroids, ostarine doesn't seem to cause as many side effects in other parts of the body.

Uses & Effectiveness?

Insufficient Evidence for

Involuntary weight loss in people who are very ill (cachexia or wasting syndrome). Early research shows that taking ostarine can increase lean body mass by a small amount in cancer patients who seem to be losing weight.

Age-related muscle loss (sarcopenia). Early research shows that taking ostarine can increase lean body mass by a small amount in elderly adults.

A group of inherited disorders that cause muscle weakness and muscle loss (muscular dystrophy).

Breast cancer. 

Loss of bladder control (urinary incontinence).

What are SARMs?

Selective Androgen Receptor Modulators (SARMs) are a class of therapeutic compounds that have similar anabolic properties to anabolic steroids, but with reduced androgenic (producing male characteristics) properties. As an example, the androgen receptor is activated by binding androgens, such as testosterone. Unlike anabolic steroids, which bind to androgen receptors in many tissues all over the body, individual SARMs selectively bind androgen receptors in certain tissues, but not in others. 

In medical settings, this could be very useful for stimulating specific tissue growth like muscle and bone, while avoiding unwanted side effects in other tissues like the liver or skin. SARMs are being evaluated as a clinical treatment for muscle-wasting caused by several diseases, such as osteoporosis, cancer, heart failure, chronic obstructive pulmonary disease, end-stage liver disease, end-stage renal disease, and HIV. To date, all SARMs are for investigational purposes only.

Are SARMs prohibited on the World Anti-Doping Agency (WADA) Prohibited List?

All SARMs are prohibited at all times (both in and out-of-competition) for all athletes, from those competing at the highest level of sport to those competing at the recreational level. SARMs are listed in the category of “Other Anabolic Agents” under section S1.2 of the WADA Prohibited List.

Examples of SARMs include: ostarine (Enobosarm, MK 2866), andarine, LGD-4033 (ligandrol), and RAD140.[3] SARMs have the potential to be misused for performance enhancement in sport due to their anabolic properties, as well as their ability to stimulate androgen receptors in muscle and bone, leading to bone and muscle growth.

ATTENTION: All these products are strictly for LABORATORY AND RESEARCH PURPOSES ONLY. They are not to be used for any human and veterinary purposes.