Ostarine

Ostarine, otherwise known as Enobosarm, MK-2866 and GTx-024, is a compound which belongs to selective androgen receptor modulators (SARMs). It is one of the most popular, safest and thoroughly tested SARMs. It is effective in increasing muscle strength and mass, boosts bone mineralisation processes and stimulates joint recovery.

Ostarine – mechanism and profile of action

Ostarine is a nonsteroidal, selective agonist of androgen receptors (ARs). It acts on the muscle and bone tissue. Because of this selectivity, SARMs are vastly superior to anabolic-androgenic steroids (AAS) which act on all androgen receptors, causing many side effects.

Due to powerful anabolic and anticatabolic effects on muscle and bone mass and beneficial impact on joints, the compound has gained great popularity among athletes and bodybuilders who need support in building muscles. Compared to other SARMs, ostarine has quite mild anabolic effects. Because of that, it is recommended to beginners and persons who need moderate support in building muscle mass.

Continued gains in muscle mass, density and strength

Ostarine competes for access to AR in muscles and bones with its natural ligands – testosterone and dihydrotestosterone. It exerts similar anabolic effects to testosterone while having minimal androgenic activity.

By binding and activating the intracellular androgen receptor in skeletal muscles, it contributes to increasing the number of myosatellite cells (stem cells of skeletal muscles) and synthesis of many muscle proteins and stimulating post-workout recovery of muscle fibres.

Studies on rodents have shown that ostarine has anabolic effects because it regulates the expression of s-adenosylmethionine decarboxylase, which is critical to the synthesis of polyamines associated with muscle hypertrophy and myostatins – inhibitors of muscle protein synthesis. Enobosarm may also promote the expression of insulin-like growth factor 1Ea (IGF-1Ea) in the muscles, which is a stimulator of muscle mass growth.

Versatile SARM for bulking up, strength and fat reduction

Since enobosarm can be used at any stage of bodybuilding, this SARM is extremely versatile. While building muscle mass, ostarine speeds up the recovery and growth of muscle tissue, allowing you to achieve impressive results in a relatively short time. Anticatabolic activity of ostarine becomes more important during a cutting phase. It gives protection against muscle loss when energy supply is limited. MK-2866 is also helpful in following a body recomposition routine, i.e. increasing muscle mass and losing fat.

Enhanced joint recovery

Another noticeable effect of taking ostarine is an improvement in the function and lubrication of joints, which is a unique feature of this SARM. This effect is observed at low doses, around 5 mg. In addition, ostarine may also reduce joint pain. The exact mechanism of this action has not been explained. However, it is known that GTx-024 may boost the synthesis of collagen – a protein of connective tissue which is a component of e.g. joint cartilage.

Due to its impact on joint recovery, ostarine may be helpful in different kinds of injuries, joint and tendon inflammation and pain cause by overstraining joints (most frequently in the shoulders and knees, e.g. “jumper’s knee”), which affect many persons doing strength workouts.

Greater bone strength

One of the main reasons for synthesis of ostarine was to fight osteoporosis, affecting especially women during menopause. By stimulating the AR in bone tissue, ostarine enhances anabolic processes in this area. It helps increase bone mineral density, reduces the risk of fractures and promotes healing of mechanical bone injuries.

Higher free testosterone levels

Studies on a group of men and women showed that enobosarm lowered levels of sex hormone-binding globulin (SHBG). SHBG binds e.g. testosterone, thereby reducing its free levels in the blood. High SHBG levels make it impossible to enjoy benefits of anabolic activity of testosterone, even when levels of this male hormone are high.

Better metabolic parameters

Ostarine has been shown to improve metabolic parameters and may be thus potentially used to treat metabolic syndrome. It can improve the blood lipid profile. The study on a group of women and men showed a decrease in total cholesterol and triglyceride levels. Nonetheless, levels of high density lipoproteins (HDL), so-called good cholesterol, were also lower. Moreover, MK-2866 may improve insulin sensitivity and lower glucose levels on an empty stomach. This effect has been observed at the dose of 3 mg.

Favourable safety profile

Compared to other SARMs, MK-2866 has a favourable safety profile and few side effects. It does not have a methyl group and thus have a smaller impact on the liver. It does not undergo aromatisation and that is why it has a minimal impact on oestrogen levels.

To sum up, Ostarine is a product with anabolic and anticatabolic effects for persons who need support in gaining dense, quality and lean muscles and want to speed up post-injury recovery of muscles and joints and strengthen their bones. It is a versatile product, recommended for all phases of bodybuilding.
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Supplementation in practice – expert advice

The risk of side effects of taking ostarine is higher when you increase the dosage and extend the cycle. As a result, it is not recommended to exceed the 8-week cycle with the maximum daily dosage of 25-30 mg. However, the effects of supplementation are noticeable even at low doses. Because of that, 10 mg of ostarine a day may be a sufficient dose in many cases to achieve the desired results. It is not required to take a long break from use after finishing a cycle. It is suggested that a break equal to the period of taking the preparation should be sufficient.

Depending on the dose, MK-2866 may have a stronger or weaker effect on the HPTA axis. As a consequence, it is recommended after discontinuing the supplement to do laboratory tests which measure levels of sex hormones and those in the pituitary gland and then to consider whether you need a therapy that will restore hormone balance, i.e. PCT. It is also recommended to have regular blood tests and monitor sex hormone levels while taking the supplement.

The half-life of ostarine is 24 h. Because of that, the product can be taken just once a day.

MK-2866 is on the list of substances banned by the World Anti-Doping Agency. This preparation should not be therefore taken by individuals who are planning to participate in contests controlled by WADA.
It is recommended to take ostarine along with creatine, magnesium or ZMA.

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4898053
https://ascopubs.org/doi/abs/10.1200/jco.2007.25.18_suppl.9119
https://www.ncbi.nlm.nih.gov/pubmed/29785666
https://www.ncbi.nlm.nih.gov/pubmed/26393303
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3177038
https://selfhacked.com/blog/ostarine

https://www.sciencescape.org/mk-2866-ostarine