Tag Archives: selective androgen receptor modulators

Selective Androgen Receptor Modulators (SARMS)

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Selective Androgen Receptor Modulators (SARMS)


MK-2866 Ostarine SARMSThe biological actions of androgens are primarily mediated by the androgen receptor. The androgen receptor is expressed in target tissues as the prostate, skeletal muscle, liver, central nervous system, with the highest expression being produced in the prostate and adrenal gland. Men with rare mutations of the androgen receptor have lower lean mass and higher body fat than normal men. The physiological importance of the androgen receptor has been demonstrated as animal studies that administer androgen receptor antagonist (drugs that block the actions of androgens binding to its receptor) during muscle overload have suppressed muscle hypertrophy. This suggests that the androgen pathway has a significant effect in exercise-induced muscle hypertrophy and emphasizes the importance of the increase in the number of androgen receptors in exercised muscle. Additionally, when scientists administered the androgen antagonist flutamide, to rats undergoing puberty resulted in a suppressed muscle growth. Researchers developed SARMS to minimize the side effects of testosterone y promoting full anabolic activity in muscle and bone, while minimizing the undesirable side effects on prostate, hair, skin, and without affecting sperm production and sex drive.

SARMS have full anabolic activity in muscle and bone, yet have minimal effect the on prostate. SARMS are highly specific to the androgen receptor as they have a 1000-fold less binding affinity for any other receptor. SARMS are orally available and so far seem to have minimal effect on the liver. SARMS have a number of beneficial effects in bone, muscle, and sexual function independent from the conversion of androgens into estrogens.

SARMS: Anabolic Activity in Muscle and Bone with Minimal Effect on the Prostate.

GW-501516-SARMSTestosterone induced increase in muscle mass is associated with hypertrophy of both type I and type II fibers and increased satellite cell activation. The effect of testosterone is thought to be mediated by the androgen receptor as muscle growth factors in vitro (in test tubes) are blocked by the androgen antagonist bicalutamide (blocks the actions of testosterone from binding to the androgen receptor), indicating that the effects of testosterone are mediated thru the androgen receptor pathway. The androgen receptor signaling pathway enhances the expression of myogenin (Myogenin is an important mediator of muscle growth) and accelerates the expression of muscle growth factors. AR expression is widespread throughout the body and androgens play a desirable role in promoting bone strength, increasing muscle mass, decreasing fat tissue, and increasing muscle strength. A study in the Journal of Steroid Biochemistry and Molecular Biology reported that when resistance trained men had muscle biopsies taken the greatest predictor of males 1-RM strength was not testosterone but the androgen receptor content in the thigh muscle. SARMS are muscle specific compared to testosterone. For example, one study reported that oral doses of SARMS exhibited a >50-fold selectivity for muscle over the prostate. Testosterone propionate had only a 2-fold selectivity for muscle versus prostate. Other studies have reported that the SARM S4 produced greater anabolic activity in muscle than testosterone propionate but had less androgenic activity on the prostate. Additionally, a study published in the journal of Endocrinology reported that SARMS were just as anabolic in muscle compared to testosterone cypionate but less androgenic. In that study, testosterone cypionate increased prostate weight and muscle growth in a dose dependent manner, meaning the more testosterone they used the more muscle hypertrophy was experienced but with similar increases in prostate growth. SARMS showed more anabolic activity in muscle with minimal stimulation of the prostate. Compared with testosterone cypionate, SARMS were more than 200 times more potent in stimulation of muscle and 80 times more selective for muscle versus prostate. Additionally, both testosterone cypionate and SARMS decreased adipose tissue in a dose dependent manner. The study demonstrated that SARMS has the potential to provide a greater safety delivery than testosterone, mainly with low stimulation of the prostate, yet hyperanabolic effects on muscle tissue. SARMS have also been shown to increase skeletal muscle strength.


S-4 bottle SARMSIt should be noted that testosterone increases muscle mass thru multiple pathways: increasing protein synthesis, increasing GH secretion, increasing IGF-1 levels, increasing satellite cell activation, and increasing androgen receptor concentration in muscle. The androgen receptor binding affinity of steroids is only partly responsible for the androgen receptor mediated effects of both physiological and synthetic steroids. For example, it is well known that some steroids are potent anabolic agents, yet bind to the androgen receptor weakly. Another interesting fact is that testosterone can increase lean body mass and reduce fat mass in androgen-deficient men. The skeletal muscle androgen receptor may exert both receptor dependent (testosterone, DHT) and independent actions (intramuscular IGF-1) in the functionally overloaded muscle, which may be related to growth factor signaling. The androgen receptor in muscle is decreased during aging which may be an important contributing factor to the age related decrease in muscle mass that occurs with aging. The development of SARMS for clinical use is promising based on preclinical data owing to their selective high anabolic activity in muscle. SARMS could be useful for the prevention of many muscle wasting diseases and age related decreases in muscle mass without unwanted side effects associated with testosterone. In addition, SARMS may be prevent or treat prostate enlargement as SARMS is a partial agonist on the prostate. SARMS also lack estrogenic activity and do not under go 5a-reduction so it can’t be converted to DHT. The side effects are minimal and the results speak for themselves. d

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Posted in Performance Enhancing, SARMS

Ostarine (MK-2866)

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Ostarine (MK-2866)


MK-2866 Ostarine SARMSOstarine (MK-2866) is a SARM that was developed for the prevention and treatment of muscle wasting. Future plans indicate that it will eventually be prescribed for the prevention of cachexia, atrophy and sarcopenia as well as for Hormone or Testosterone Replacement Therapy.

The way that ostarine works by binding to the androgen receptor demonstrating bone and muscular anabolic activity. Ostarine causes muscle growth by binding and activating the androgen receptor, which alters the expression of genes and increases protein synthesis. Ostarine exerts its anabolic effects on muscle tissue almost exclusively. It also minimizes atrophy during recover periods from surgeries and injuries making it desirable for so many different types of users and situations. Ostarine is extremely effective in maintaining and gaining lean body mass.

Ostarine USES:

Ostarine is extremely versatile and can be used for every type of goal in training. It can be used to bulk, to cut or to recomp. It truly shines as a recomp but provides effects in all three areas.

As a bulker, ostarine has shown to add up to 7 lbs. of lean muscle mass over an 8 week cycle. The optimal dose is 25 mg a day. The half life of ostarine is very long so it only needs to be taken once a day, preferably in the morning. Ostarine is the most anabolic of all the SARMS, so it provides the best chance of muscle gain. The gains that ostarine provides are very keepable and the muscle and size gained is very lean and clean. There is a significant strength increase as well.

As a cutter, ostarine should be dosed at 15-20 mg a day for 8 weeks. Ostarine would primarily fit into a cutting protocol for the maintenance of muscle mass while reducing calories. One of the most disheartening outcomes of cutting is the loss hard earned muscle mass. The drop in metabolic rate and hormone levels (T3, IGF, Testosterone, etc) with the lack of calories is a perfect catabolic environment for loss of muscle tissue. As Ostarine has anabolic effects, user can cut calories without having to worry about muscle or strength loss. Ostarine has also shown noticeable nutrient partitioning effects among users, another reason why it can be of great help when cutting.

Ostarine truly shines during a recomp. Ostarine works particularly well during a recomp because of its nutrient partitioning benefits. Calories are taken from fat stores and calorie intake is fed to the muscle tissue. Many users have shown that when ostarine is consumed at maintenance calories, they are able to lose weight yet still show increases in strength and muscle mass. Although Ostarine is taken orally, it is not methylated and is not toxic to the liver and does not have a negative effect on ones blood pressure. Therefore it can be run for longer than oral steroids. Ostarine can be used up to 12 weeks safely and still provide excellent benefits.

Injury Prevention:

Ostarine also has the benefit of healing as part of its versatility. The effects it provides translate to anabolism in bone and skeletal muscle tissue, which also allows it to be used in a variety of ways, such as treating osteoporosis and in conjunction with drugs that reduce bone density. It has excellent benefits when used for rehabilitation of injuries, especially bone and tendon related injuries.

Doses of 12.5mg per day is recommend for such purposes and improvement in joint movement that can be seen after just 6-8 days.

Estrogen Concerns:

SARMS do not aromatize, conferring all their effects to AR binding and not to metabolic conversion to active androgens/estrogens. However blood work from users has shown a slight elevation in serum estradiol levels (which may be one of the factors in its high effectiveness for treating tendon, ligament, and bone injuries or illnesses.

This elevation is extremely small and is no case for concern. If however you are absolutely concerned about slight increases in Estrogen, you can always opt for low doses AI’s, like aromasin or arimidex for added protection and prevention. The use of D-Spark is highly encouraged as opposed to an AI on cycle. Most instances where there have been gyno concerns are due to users abusing the dosing and exceeding the recommended 25 mg a day… Exceeding 25 mg a day is not advisable and when side effects start to occur.

Slight Suppression:

Ostarine has shown to be slightly suppressive when ran over 4 weeks. It is nothing to be alarmed about and nowhere near like running a steroid. HcGenerate is highly encouraged to be used on cycle to keep suppression to a minimum and to transition into pct smoothly. A 3 week mini pct is required after ostarine use is completed. HcGenerate ES ran for 3 weeks will provide the optimal recovery. A SERM can be used but it not required for pct. Recovery on SARMS is very quick and smooth as long as it is done properly.

Ostarine advantages and benefits:

Ostarine Summary

  • Anabolic even at doses as low as 3mg
  • Great for strength
  • Great for lean mass gains
  • Great for body recomposition
  • Great for endurance (aerobic or anaerobic)
  • Joint healing abilities
  • Half life of circa 24 hours – only once a day dosing required
  • It is non methylated so it is non toxic to the liver or blood pressure
  • Some suppression may be present at doses of 25mg+ run for longer than 4 weeks, however a stringent PCT of prescription SERMs like Nolvadex or Clomid is not necessary.
  • High oral bioavailability without significant damage to your liver as with oral steroids.
  • Great sense of well being while on, (without the aggression which can often detrimentally impact users daily lives).
  • No need for a long time period off between cycles; the recommended time of period for normal steroid cycles would be Time on + PCT, so for a typical 6 week cycle and 4 week PCT, a user would have to wait another 10 weeks afterPCT to start another cycle where SARMS recovery requires minimal rest in between.
  • Ostarine also resulted in a dose-dependent decrease in LDL and HDL cholesterol levels, with the average LDL/HDL ratio for all doses remaining in the low cardiovascular risk category – hence there is little impact on cholesterol values.

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Posted in Anabolic, SARMS