Selective Androgen Receptor Modulators (SARMs): Ostarine and Andarine

Selective Androgen Receptor Modulators (SARMs): Ostarine and Andarine

Selective Androgen Receptor Modulators (SARMS): Ostarine and Andarine 

The term “SARMS” stands for “Selective Androgen Receptor Modulator”. Androgens, specifically, are a class of hormones that serve as ligands (molecules that bind to another), which bind to cellular androgen receptors. The binding of the androgenic hormones, testosterone, or Dihydrotestosterone (DHT) in the cytoplasm and “translocating” into the nucleus activates these androgen receptors. The primary function of the androgen receptor serves as a DNA-binding transcription factor that regulates gene expression. Once you read through this

For those familiar with steroids and prohormones, they offer muscle building properties through this same binding method to the androgen receptors.

Simply put, any drug or compound that can block and/or stimulate these nuclear hormone receptors selectively, is known as a selective receptor modulator. SARMS are capable of this method of blocking / stimulating a receptor in a tissue-specific manner, which allows it to mimic the effects of traditional steroids and prohormones, without the unwanted effects in other tissues (secondary and sex organs).

The appeal of these SARMs, which are relatively new to the bodybuilding and fitness industry, are just that, that they provide the benefits of traditional anabolic steroids, such as increased testosterone, increased muscle mass, fat loss, and bone density, all the while, offering a much lower capacity to produce the traditional unwanted side effects that come with anabolic steroid use.

Because of their ability to facilitate such desirable results, they’re viewed as a new, unique class of compounds that are currently undergoing extensive investigation, research, and development from a number of pharmaceutical and sports supplement companies.

UPDATE: Once you get through this article, we highly recommend reading our 3 Best Ostarine Supplements review as well.

SARMs vs. Anabolic Steroids

Traditionally, steroids have been prescribed for two specific reasons; to fight muscle-wasting diseases (cancer, osteoporosis, etc.) and for hormone replacement therapy. For those who have taken steroids or prohormones in the past, you’re familiar with the common side effects associated with them, which include, but are not limited to:

  • Gynecomastia (male breast development)
  • Liver toxicity
  • Testosterone suppression
  • Cholesterol imbalances
  • Body hair growth
  • Acne; and
  • Stimulation for prostate cancer

This partial list aside, there’s also the concern of injection, fear of needle use, and an overall lack of knowledge as it relates to proper dosing, liver protection, post-cycle therapy, and legality protocols.

The primary difference, as it relates to SARMs, is that they’re designed to stimulate a receptor in a tissue-selective manner (bone and muscles, specifically).

By doing this, it’s possible to mimic the beneficial effects of anabolic steroids to the muscle and bone tissues, while minimizing / eliminating unwanted effects to other major tissue groups. With this understanding, it’s this selective process that allows these selective receptor modulators to be able to create muscle growth.

So, to reiterate, SARMs provide the potential to harness the benefits of anabolic steroid use, while minimizing the toxic, long-term side effects. They provide a host of advantages, starting with the means of ingestion. SARMs are taken orally, either by capsules or liquid drops (no injections), which many of the most effective steroid and testosterone options are not.

Benefits of SARMs

SARMs can be use to accomplish a number of goals, which include:

  • Prevention of muscle wasting during calorie deficits (cutting)
  • Increased fat loss
  • Increased muscle growth
  • Injury rehabilitation; and; and
  • For post-cycle therapy (PCT) use after a steroid/pro hormone cycle

As a standalone supplement, those are clearly pretty impressive. But, when you understand the benefits of SARMs when compared to steroid use, they quickly become the clear alternative solution for your fitness, bodybuilding, and physique agenda. Let’s break it down a bit further. When compared to steroids, SARMs offer additional benefits, such as:

  • Oral use (no more injections)
  • No liver toxicity
  • Legal
  • No conversion to estrogen
  • No conversion to Dihydrotestosterone (DHT)
  • Similar effect of increased testosterone (libido, fat loss, lean muscle gains); and
  • Undetectable (selected SARMs)

With this understanding of the mechanisms in which SARMs work, it’s pretty clear to see how effective their potential is in terms of providing a clean, safe alternative to anabolic steroids.

Two Most Popular SARMs: Ostarine and Andarine

There are a number of pharmaceutical companies currently analyzing and testing the potential claims and efficacy of selective androgen receptor modulators, due to their “highlight worthy” benefits. And in fact, there are hundreds of potential SARMs undergoing this investigative process. But, there are only two primary SARMs available, with proper applications for bodybuilders, power lifters, fitness enthusiasts, and athletes at this time.

These two are known as Ostarine (MK-2866) and S-4 (Andarine).

Ostarine (MK-2866) CompoundOstarine (MK-2866)

Otherwise known as ((2S)-3-(4-cyanophenoxy)-N-[4-cyano-3-(trifluoromethyl)phenyl]-2-hydroxy-2-methylpropanamide for those that can pronounce it, was originally developed for the prevention and treatment of muscle wasting. With the extensive research being done for medical claims, it may eventually be medically prescribed for the prevention of cachexia, atrophy, and sarcopenia, as well as hormone and testosterone replacement therapy.

Ostarine effectively binds to the androgen receptor and demonstrates osteo- (bone) and myo- (muscular) anabolic activity.

Ostarine Uses

Bulking: Ostarine is the most anabolic of the two SARMs, making it first and foremost effective in increasing lean muscle. Social proof, in the form of user reviews, have shown that the lean muscle gains obtained through the use of Ostarine are very maintainable. Many reviews have shown increases of 7-9 pounds of lean body mass over an 8-week cycle, at a dose of 25mg per day.

Generally speaking, the higher the daily dose, the higher the testosterone suppression. Although suppression is minimal, relative to suppression realized post-steroid use, we recommend a “mini” 3-4 week PCT for any cycle extending past four [4] weeks.

Cutting: During a state of caloric deficit, Ostarine is particularly effective in the maintenance of muscle mass. As with most cutting phases, decreases in metabolic rate and hormone levels are almost always inevitable for those not considered “professional” at cutting.

Ostarine allows you to cut calories without having to worry about muscle and strength decreases, and has also been shown to aid in nutrient partitioning. With the anabolic effects of Ostarine, those cutting should maintain a daily dose of 15-20mg for roughly 6-8 weeks without experiencing any side effects or a noticeable amounts of testosterone suppression.

Recomposition: For most, the ability to lose fat, while simultaneously gaining lean muscle, is the ideal feat. Again, due to its nutrient partitioning benefits, Ostarine is effective in taking fat stores and an increased calorie intake to feed muscle tissues.

When recomping, “time is king”. While trying to accomplish multiple objectives (lose fat AND gain muscle), progress requires a longer duration. For those worried about liver toxicity during extended periods of use, because Ostarine is taken orally, it isn’t methylated, alleviating negative effects on the liver and blood pressure. We recommend dosing at 20-25mg for roughly 6-8 weeks, with an optimized diet (calories just above maintenance).

Ostarine Half Life & Timing of Doses

Ostarine has a half-life of 23.8 hours (we’ll round up to 24 hours, for simplicities sake), which allows for a single dose, once per day.

Best Ostarine Supplement – DISCONTINUED

UPDATE: It’s come to our attention that there is a large degree of pending litigation surrounding the supplement “Ostarine” right now. This has caused virtually every supplement brand that manufacturers and distributes Ostarine to cease ALL sales immediately.

It pains us to see this happen to these great companies and great products, but facts are facts. Currently, Ostarine isn’t an FDA approved supplement. For all of you Ostarine lovers, you’ll just have to bide your time until Ostarine is approved for human consumption as a dietary supplement. 

Best Ostarine Supplement -REPLACEMENT

If you’re considering an alternative to ostarine, we highly recommend taking a look at our list of the best epicatechin supplements.

Considered to be one of the most natural, anabolic antioxidants, epicatechin has been proven to provide a number of awesome muscle-building benefits:

  • Increased muscle growth, strength, and endurance
  • Increase nitric oxide levels and muscle pump
  • Myostatin inhibitor
  • Increased blood flow
  • Improved blood pressure; and
  • Lowers cholesterol

If you’ve already used epicatechin, then you’re already well aware of its anabolic nature.

If this is your first time trying it, you’re going to be incredibly pleased with it’s results.

During our epicatechin research, we came across Anabolic Iron, who has the best epicatechin supplement that we’ve found yet.

As the only “hardcore” supplement company that offers 100% formula transparency, Anabolic Iron’s epicatechin includes:

  • 125mg of Epicatechin (95% purity); and
  • 400mg Green Tea Extract

As far as dosage, purity, and servings go, Anabolic Iron has the best epicatechin supplement that we’ve ever seen.

If you’re looking for a serious boost in your workouts, and supplement regimen, we highly recommend Anabolic Iron.

Andarine S-4 CompoundAndarine (S-4)

In terms of most effective use, Andarine performs best during a cutting phase.

Andarine Uses

Due to its binding affinity of androgen receptors, specifically, towards adipose tissue development, it provides impressive fat burning effects. Research also shows effective in decreasing lipoprotein (LPL), which is an enzyme responsible for lipid accumulation (storing fat).

Due to its anabolic and androgenic effects in muscle tissue, Andarine helps to aid in fat loss, while maintaining, and sometimes increasing muscle mass while cutting. User reviews share that it significantly increases vascularity and promotes a quality, “hard” look, with very little water retention.

We recommend a daily dose of 50mg for roughly 6-8 weeks, while cutting. However, due to some vision side effects, we recommend following a “5 on, 2 off” format, where Andarine is taken for 5 days, followed by a 2 day break, for 6-8 weeks.

Andarine Half Life

With a very short half life of 2.6 hours, we recommend taking Andarine roughly 2 hours prior to your workouts, in order to maximize efficacy during strength training.

SARMs Summary

Clearly, SARMs haven’t made their way throughout the mainstream supplementation industry at this point in 2015, but with their incredible potential, we fully anticipate seeing them continue to rise in the ranks as one of the elite supplement categories for bodybuilders and athletes, alike.

And, as always, we appreciate you taking the time to spend part of your day with us here at Supplement Demand. We put a lot of time and resources into making sure that our readers are among the most educated and well-informed on the internet. If, and when, you decide to move forward with one of our recommended Ostarine and/or Andarine supplements, check back with us and let us know how your experience was!


  • Juan 6 years

    Ostarine sounds like some incredible stuff. Do you have a product you recommend?

    • Matt B. 6 years

      Hey, Juan! We recommend Ostarine by Thanos Labs, as it’s the perfect daily dose to meet most fitness regimens. Check out our top 3 Ostarine Supplements article, you can read more about it there.

      Also, receive free shipping by using “suppdemand” at checkout!

    • Supplement Demand 6 years

      Hey, Juan! We recommend Ostarine by Thanos Labs, as it’s the perfect daily dose to meet most fitness regimens. Check out our top 3 Ostarine Supplements article, you can read more about it there.

      Also, receive free shipping by using “suppdemand” at checkout!