Install the app
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

Ostarine (MK-2866)

drtbear1967

Musclechemistry Board Certified Member
Ostarine (MK-2866) is a SARM developed by GTx for the prevention and treatment of muscle wasting. It may eventually be a medical prescription for the prevention of cachexia, atrophy and sarcopenia as well as for Hormone or Testosterone Replacement Therapy.As a research chemical, Ostarine belongs to a class of chemicals know as SARMS or selective androgen receptor modulators. SARMS create selective anabolic activity at certain androgen receptors. In comparison to testosterone and other anabolic steroids, the advantage of SARMS, is they do not have androgenic activity in non-skeletal muscle tissues. Ostarine is effective in maintaining and increasing lean body mass.

How does it work?SARMS bind to the androgen receptor and demonstrate osteo (bone) and myo (muscular) anabolic activity.

Androgen receptor activation
Binding and activation of the Androgen receptor alters the expression of genes and increases protein synthesis which builds muscle. In essence, SARMS like ostarine cause muscle growth in the same manner as steroids, however unlike testosterone and other anabolic steroids, SARMS do not produce the growth effect on prostate and other secondary sexual organs. Ostarine in particular exerts its anabolic effects on muscle tissue almost exclusively. So not only does it represent a new potential treatment option for a wide spectrum of conditions from muscle wasting diseases (from age-related to AIDS or cancer-related), but is also has immense potential for muscle building for bodybuilders, fitness, athletes and an agent to minimize atrophy during recovery periods from serious surgery or similar situations.
Uses of Ostarine
Lean muscle gains (bulking)Ostarine is the most anabolic of any SARMS, making its first and foremost use for wanting to gain lean muscle. The gains in total weight will not be comparable to bulking steroids, however the total gains will almost entirely be lean muscle. The gains that are made on ostarine are very keepable and users generally see an increase of up to 7 lbs. of lean body mass over and 8 week cycle at 25mg day (diet dependent). The most common dosage is 25 mg for 8 weeks. The side effects that one encounters with steroid use will not be present on cycle. Generally, with ostarine, the higher the dosage, the more suppression. Although suppression is minimal and is nowhere comparable to suppression that one encounters on steroids, any cycle of ostarine over a 4 weeks period requires a 3 week mini pct. A serm is not required in this pct. Losing Bodyfat (cutting)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, the dieter 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.A 15-20 mg dosing protocol for 6-8 weeks is good for cutting with Ostarine without undergoing any side effects or high suppression. However it must be stated that due to the lack of androgenicity, muscle hardness and overall results are not as prominent as with the SARM S-4. Recomping Recomping is where ostarine truly shines. The recomping effect of losing fat and gaining muscle at the same time is what the majority of users are looking for. Trying to achieve this when you are not absolutely new to training is extremely difficult.Where Ostarine shines for recomping is in its nutrient partitioning benefits. Calories are taken from fat stores and calorie intake is fed to the muscle tissue. In fact many users report that Ostarine consumed at maintenance calories produces weight loss, while still getting increases in strength and muscle mass. One of the most important factors of recomping is time. As you are trying to achieve multiple objectives, it requires a longer time period to notice good recomp effects so even when running steroids, these would have to be longer run injectable compounds as opposed to the short used liver toxic oral steroids.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. The dosing protocol of 20-25mg for 6-8 weeks will give excellent recomp effects.Diet must also be optimized to where calories are just above maintenance with at least 30% coming from lean sources of protein to get the best recomp effect.Injury PreventionThe effects of ostarine translate to anabolism in bone and skeletal muscle tissue, which means it could be used in the future for a variety of uses, such as osteoporosis and as a concurrent treatment with drugs that reduce bone density. Therefore it has great application as a compound to use for rehabilitation of injuries, in particular 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.Timing of DosesAs Ostarine has a half life of around 24 hours, each of these doses only has to be taken orally once a day, therefore its also offers an extremely convenient supplementation intake.Ostarine and estrogen concernSARMS 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.
Advantages of Ostarine when compared to steroids


  • 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 after PCT 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.

Advantages Of Ostarine when compared to other SARMS


  • The metabolite M1 which seems to cause toxicity in S4 (temporary occular disturbances) is not present in Ostarine.
  • Also unlike S4, Ostarine does not have androgenic properties in non muscle tissue.


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
 
Last edited by a moderator:
Back
Top