SARMs: Everything You Need To Know

man considering whether or not to take SARMs

If you’re reading this, it’s probably because you’re considering using SARMs or, at the very least, you’re interested in learning more about them.

Well, you’re not alone!

In recent years, we’ve seen an explosion in the number of people using SARMs.

These unique substances are appealing to everyone from bodybuilders and athletes to the average Joe who just wants to get bigger and stronger faster than any natural substance would permit.

SARMs offer a way to get ahead without many of the negatives side effects associated with steroid use.

At least, that’s the pitch…

The truth is, even the most extensively-researched SARMs have only been studied in human beings a few times.  Most of them haven’t been studied in humans at all.

Thus, much of the narrative surrounding SARMs is influenced by the incredible marketing claims made by companies that sell them.

According to them, SARMs are “almost as effective as steroids” but “won’t cause any negative side effects”.

In other words, you can have your cake and eat it too!

But is this really true?

Can SARMs really help you build considerable amounts of muscle?

Do they carry any risks or side effects?

Are they even legal?!

Don’t worry, in this article we’ll answer all your questions about SARMs by taking a hard look at the scientific research behind some of the most popular compounds.

Before we get started, though, let me just make one thing crystal clear.

I’m not going to preach to you about what you should and shouldn’t put in your body.

It’s YOUR body.

My goal is simply to help you develop a deeper understanding of SARMs so you can make a more informed decision about whether they’re for you.

If you’re sick of reading a bunch of industry-influenced nonsense about SARMs–with no scientific basis for many of the claims being made–you’ve come to right place.

By all means, read on…

What Are SARMs And How Do They Work?

capsules spread out across the table

The term “SARM” is an acronym which stands for Selective Androgen Receptor Modulator.

SARMs work by selectively targeting androgen receptors in certain tissues (like muscle and bone) but not in other tissues (like the prostate, liver, and brain).

This is in contrast to steroids which saturate androgen receptors everywhere with no selectivity.

The most popular SARMs are:

  • LGD-4033 (Ligandrol)
  • MK-2866 or GTx-024 (Ostarine)
  • S-4 (Andarine)
  • YK-11

For the sake of simplicity, GW-501516 (Cardarine) and MK-677 (Ibutamoren) are commonly referred to as SARMs, but they’re actually not.

We’ll talk about all of these SARMS (and the other compounds as well) a little later on, but first we need to develop a solid understanding of how exactly SARMs do what they do.

In order to understand that, we must first understand a little about our hormones.

Hormones function as the chemical messengers of the body.  They carry instructions on how the body should function, signaling all sorts of changes and carrying out important bodily functions.

Androgens are sex hormones that regulate the development and maintenance of male characteristics (deep voice, muscle mass, sexual wellbeing, etc.).

When we talk about Androgens, we’re usually referring to the most well-known Androgen, Testosterone.  There are others, but Testosterone is definitely the most important for muscle growth.

When you use steroids, they saturate androgen receptors all throughout the body.

So yeah, they increase muscle mass, bone density, and burn fat, but they also saturate androgen receptors in places where damage can occur (the prostate, liver, and brain).

SARMs on the other hand, selectively target muscle and bone tissue without saturating androgen receptors in other tissues (like the prostate, liver, and brain).

This is why SARMs have developed a reputation for being much safer alternatives to steroids and the evidence so far indicates that reputation is warranted.

A Closer Look At Some Of The Most Popular SARMs

There are several known SARMs, each of which have varying amounts of research behind them.  There are also some compounds which have been incorrectly labeled as SARMs and grouped in with the rest of them.

We’ll talk about those as well.

First, let’s tackle a few of the most popular SARMs head on–from a scientific research perspective–in order to determine which ones are the most promising and which ones you may want to hold off on for now.

LGD-4033 (Ligandrol)

LGD-4033, also referred to as Ligandrol and Anibolicum, is one of the most well-researched SARMs.

It was originally developed by Ligand Pharmaceuticals and is now undergoing clinical trials by Viking Therapeutics, under the name VK-5211.

This would be a good time to mention that when I say “well-researched”, what I really mean is “well-researched relative to other SARMs”.

The reality is none of these compounds have been as extensively-researched as steroids or natural muscle-building supplements (like Creatine).

That said, the preliminary research on LGD is pretty encouraging so far.

In healthy human subjects, LGD-4033 has been shown to dose-dependently increase lean muscle mass at doses ranging from 0.1-1mg (with 1mg being the most effective).

A safety study also found that 22mg/day did not cause any immediate, noticeable side effects.

It’s worth mentioning that LGD-4033 did suppress natural Testosterone production at 1mg/day, with levels returning to normal after a couple weeks off.

It’s possible that higher doses lead to more severe, long-lived suppression, so it may be a good idea to use a PCT of some kind when coming off LGD.

MK-2866 (Ostarine)

MK-2866, also known as Ostarine and Enobosarm, is perhaps the most popular SARM of them all.  It is currently in development by GTx (a pharmaceutical company) and has had some pretty encouraging results in Phase I and Phase II clinical trials.

As far as research is concerned, MK-2866 is the furthest along out of all of the SARMs developed in the last decade or so.

It has been shown to increase lean muscle mass without impacting androgen function outside of muscle and bone tissue in elderly subjects.

The interesting thing about MK-2866 is that it appears to work without exercise, capable of increasing muscle mass at about 1 pound/month.

Combined with exercise, one would think, the gains should be much greater.

Like LGD, some testosterone suppression may occur with Ostarine so using a PCT supplement of some kind is recommended.


RAD140 appears to be a potent, highly bio-available SARM, with some pretty encouraging animal studies indicating that it can stimulate muscle growth without impacting prostate and/or liver function.

Unfortunately, RAD140 is still in pre-clinical trials so no studies have tested the effects on human subjects so far.

However, the preliminary results indicate that we’re looking at another highly bioavailable SARM, similar to Ostarine and LGD in terms of potency.

S-4 (Andarine)

S-4, also known as Andarine, was developed over a decade ago and served as the prototype for later SARMs.

It was originally developed as a potential treatment for Osteoarthritis.

In mice, it has demonstrated the same basic properties as the more advanced SARMs:

  • Increased bone density
  • Minimal impact on sex organs

Since it’s inception, however, S-4 has taken a backseat to the more powerful SARMs like Ostarine and LGD.

It’s unlikely that Andarine will ever become an approved drug, but you can still find it available from plenty of research chemical vendors and many people choose to stack Andarine with other SARMs.


Out of all the SARMs we’ve discussed, YK11 has been researched the least.

It has demonstrated anabolic effects in vitro, and enough research has been conducted to classify it as a steroidal SARM, but that’s about it.

No human studies to speak of, or even animal studies for that matter.

Most of the information you’ll read about YK11 is completely made up, either by the people who sell it or people who just want to pretend they know what they’re talking about.

In reality, nobody really knows how effective YK11 is or what the risks are…

Except those who have actually taken it, of course.

GW-501516 (Cardarine)

GW-501516, also known as Cardarine, is often grouped in with SARMs because it’s part of the same new wave of synthetic muscle-building compounds.

But it’s actually NOT a SARM at all.

Cardarine is actually a Peroxisome Proliferator-Activator Receptor-delta (PPARδ) agonist.  It has no impact on androgen receptors and does not appear to induce muscle growth, at least no directly.

It’s marketed to athletes and  bodybuilders, though, as a performance enhancer.

Cardarine is allegedly capable of increasing endurance and burning fat.

It’s basic mechanism (PPARδ agonist) suggests it may be effective, but so far there have been absolutely no human studies upon which to draw conclusions.

All we have is some rodent research and some anecdotal evidence from people who have taken it.

MK-677 (Ibutamoren)

MK-677, like Cardarine, is often mis-categorized as a SARM.

It’s actually something entirely different though…

A growth hormone secretagogue, meaning it can enhance secretion of Growth Hormone (GH).

Unlike Cardarine, MK-677 has actually been studied in humans.

It has been shown to:

So, although MK-677 is still in the early stages of clinical trials, it does appear to work.

Again, since it’s not a SARM, it has no impact on sex hormones and does not cause any kind of hormonal suppression.

Do SARMs Have Any Side Effects?

man gasping

The popularity of SARMs for building muscle is partly fueled by the notion that they “don’t cause side effects like steroids”.

While it’s certainly true that most SARMs appear to cause less severe side effects than most steroids, to say that they don’t cause any side effects at all is a bit of a stretch.

Most of the studies which have looked at the influence of various SARMs on Testosterone have found some suppression of natural Testosterone levels, a common side effect of steroid use.

The good news is that the suppression doesn’t seem to be as severe or long-lasting as that which occurs with most steroids.

Then again, most people are taking much higher doses than what has been studied clinically.

So, if you’re taking 4 times the LGD-4033 that has been shown to suppress natural Test, does that mean you’ll have 4 times the natural Test suppression?  Nobody really knows.

All in all, while SARMs do appear to be less likely to cause side effects than Testosterone, it’s probably a good idea to use some kind of PCT supplement while coming off them.

Are SARMs Legal?

SARMs are not legally available as dietary supplements.  Any company that is selling SARMs labeled as dietary supplements is violating a handful of laws.

At this time, SARMs are legally classified as “unapproved drugs”.

They aren’t scheduled, so it’s not illegal to possess, buy, or sell them, but it’s definitely illegal to call them dietary supplements and sell them for the purposes of human consumption.

Because of that, you’ll find most SARMs being sold as research chemicals with a disclaimer saying something like “Research purposes only.  Not for human consumption”.

Obviously, they are being sold for human consumption, but this is America and legal loopholes can be found and exploited across every industry.

This is simply a legal gray area where drugs that aren’t approved yet and haven’t been scheduled can be bought and sold.

It’s worth mentioning though, that if any of these currently unapproved SARMs does gain FDA approval as a drug, the pharmaceutical company that sells it probably won’t take kindly to all the knock-off research chem websites.

It’ll be interesting to see how that all pans out…

For now though, you as the consumer, are legally free to go buy all SARMs you want, just as long as they’re “not for human consumption” and are “for research purposes only” *wink wink*.

Where To Buy SARMs

Since they cannot legally be sold as dietary supplements, you’ll find SARMs for sale from bunch of research chemical vendors.

Most of the guys who sell SARMs are shady to say the least and I wouldn’t be surprised if many of them were intentionally under-dosing their products or spiking them with actual steroids to try to make them ‘more effective’ (at the expense of the unaware consumer).

Don’t make the mistake of thinking ‘SARMs are SARMs’.

Where you buy your SARMs is not a decision your should make lightly.  Choose carefully!

The Bottom Line On SARMs

Bodybuilder looking straight-forward

SARMs offer an intriguing alternative to traditional steroids because they’re capable of helping you pack on muscle mass, but without many of the negative consequences of steroid use.

While the claim that “SARMs cause no negative side effects” is a bit of a stretch, they do appear to be a lot safer than steroids.

At least, based on the preliminary research…

The reality is that many people who are using SARMs to build muscle are taking much higher doses than what has been deemed safe in the eyes of science.

We’re really not sure what the long-term health implications are for large doses taken over a prolonged period of time.

If you decide to use SARMs to pack on some muscle mass, maybe start with a low-ish dose for your first cycle before deciding whether or not to increase the dose.

And be sure to leave a comment and let me know how it goes!

Have anything to add about SARMs?  Any experiences You’d like to share?  Comment Below…

I’m Matt Theis, founder of SuppWithThat, Momentum Nutrition, and Singular Sport. I created SWT to separate the science from the hype and publish accurate, research-based information on supplements. If you like what I have to say here, feel free to check out my supplements at and

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