Twelve weeks of treatment with 3 mg ostarine per day (Study)


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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.

Dalton JT1, Barnette KG, Bohl CE, Hancock ML, Rodriguez D, Dodson ST, Morton RA, Steiner MS.
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1GTx, Inc., 175 Toyota Plaza, Memphis, TN 38103 USA.



Cachexia, also known as muscle wasting, is a complex metabolic condition characterized by loss of skeletal muscle and a decline in physical function. Muscle wasting is associated with cancer, sarcopenia, chronic obstructive pulmonary disease, end-stage renal disease, and other chronic conditions and results in significant morbidity and mortality. GTx-024 (enobosarm) is a nonsteroidal selective androgen receptor modulator (SARM) that has tissue-selective anabolic effects in muscle and bone, while sparing other androgenic tissue related to hair growth in women and prostate effects in men. GTx-024 has demonstrated promising pharmacologic effects in preclinical studies and favorable safety and pharmacokinetic profiles in phase I investigation.

A 12-week double-blind, placebo-controlled phase II clinical trial was conducted to evaluate GTx-024 in 120 healthy elderly men (>60 years of age) and postmenopausal women. The primary endpoint was total lean body mass assessed by dual energy X-ray absorptiometry, and secondary endpoints included physical function, body weight, insulin resistance, and safety.

GTx-024 treatment resulted in dose-dependent increases in total lean body mass that were statistically significant (P < 0.001, 3 mg vs. placebo) and clinically meaningful. There were also significant improvements in physical function (P = 0.013, 3 mg vs. placebo) and insulin resistance (P = 0.013, 3 mg vs. placebo). The incidence of adverse events was similar between treatment groups.

GTx-024 showed a dose-dependent improvement in total lean body mass and physical function and was well tolerated. GTx-024 may be useful in the prevention and/or treatment of muscle wasting associated with cancer and other chronic diseases.


Twelve weeks of treatment with 3 mg ostarine per day
The successors of the anabolic steroids are called SARMs, and their development is well advanced. The spiritual father of the SARMs, James Dalton, recently published a study in which he tried out the SARM ostarine on 120 healthy men and women. The new drug was not completely without side effects, but it worked.

SARMs fit in the androgen receptor, but do not have a steroid structure. The enzymes that turn anabolic steroids into compounds with all kinds of unwanted effects can therefore do nothing at all with SARMs. That means they have fewer side effects. Hope scientists.

James Dalton, the founder of GTx, is the big man in the field of SARMs. He and his co-workers made andarine, which is also known in chemical sports as S4 [structural formula below right]. They also made ostarine, which you might also know as GTx-024, MK-2866 or enobosarm [structural formula below left]. Just like andarin, ostarine has now emerged in the chemical sport. German researchers found it in preparations that sold web shops open and bare.



In the 3 mg dose, ostarine increased the fat-free mass by 1.4 kg. That effect was statistically significant. Ostarine also increased the power that the test subjects developed on a stair climber. The test subjects did not train.
The fat mass decreased slightly by 300 grams in the 3 mg group. That effect was also statistically significant.

Doctors hope that SARMs do not suppress the body's own testosterone production in men. The table below - which only concerns the men in the study - below shows that ostarine does a bit of that. A little bit.



Ostarine lowers the 'good cholesterol' HDL level. That effect is also not very strong, but in a discussion of Dalton's study, two German specialists are still a bit worried about it. [J Cachexia Sarcopenia Muscle. 2011 Sep; 2 (3): 121-123.] " The HDL decrease is still of some concern as this is a proof that there are still unwanted side and not tissue-selective effects or this novel non-steroidal selective androgen modulator ", they write.

Ostarine, just like 17-alpha-methyl-anabolics, probably does burden the liver to a greater or lesser extent. In Dalton's research, the concentration of the enzyme alanine aminotransferase [ALT] increased in twenty percent of the subjects. A high ALT level can indicate liver damage.

After all, Dalton also looked at whether women got more body hair from ostarine. That was not the case.
" GTx-024 provides beneficial anabolic effects on total lean body mass and physical function without the adverse consequences often seen with testosterone and other anabolic steroids, " the study concludes. " These data support the development of GTx-024 for treatment and prevention of muscle wasting in patients with chronic diseases ."
J Cachexia Sarcopenia Muscle. 2011 Sep; 2 (3): 153-161.


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