Everything You Need To Know About YK11

man showing muscle gains from yk11

If you’ve been paying attention to the SARM wave, you may have heard of YK11.

As a muscle-builder, it’s supposedly more powerful than any other SARM, on par with actual steroids, but doesn’t cause many of the side effects associated with steroid use.

Well, that’s the sales pitch at least…

The truth is, very little is known about YK11 at all, let alone how effective of muscle-builder it is or how safe it is.

Pretty much everything you read on the internet about it is completely fabricated.

It’s either made up by the companies that sell YK11 or just based on the subjective experiences of people who have used it.

So, I figured it’s about time someone put together an article that sums up what we know AND what we don’t know about YK11, with as little speculation as possible.

You know, the WHOLE story.

Here we go…

What Is YK11 And How Does It Work?

YK11 is a synthetic steroid compound which is commonly labeled as a Selective Androgen Receptor Modulator, or SARM.

There’s a lot of confusion about whether to classify YK11 as a SARM or as a steroid, but from a chemical standpoint, it’s definitely more like a steroid.

Research shows that YK11 is a partial agonist of androgen receptors which may act as a SARM but, at the molecular level, it doesn’t resemble SARMs like Ostarine and Ligandrol.

In fact, it fits the chemical definition of a steroid entirely because it possesses a steroid back-bone.

If anything, YK11 should be considered a ‘steroidal SARM’.

It’s chemical structure is similar to Testosterone and it appears to produce moderately potent anabolic activity.

Still, since not much is known about this compound, it could very well be as powerful (or more powerful) than some steroids.

Which brings us to the research (or lack thereof)…

Is There Any Actual Research On YK11?

YK11 is one of the latest SARMs to appear on the scene, but given the bold claims made by the companies that sell it about how powerful a muscle-builder it is, you would expect there to be some research behind it.


There isn’t.  At least, not any concrete, human research.

In fact, there’s not even any rodent studies right now.

In vitro (in living cells, but not in a living organism), YK11 has been shown act as a partial androgen agonist, producing anabolic activity that is greater than that of Dihhydrotestosterone (DHT).

Beyond the androgenic effects, this is believed to be the result of YK11 inducing the expression of Follistatin.

Follistatin is a protein which regulates muscle growth in a ‘yin yang’ fashion with another protein, Myostatin.

  • Follistatin triggers muscle growth
  • Myostatin stops muscle growth.

By increasing Follistatin activity, YK11 could potentially be quite powerful in terms of the muscle-building benefits.  Perhaps more so than the average SARM.

Unfortunately, there are literally NO studies in living animals, let alone humans.

So, for now, the benefits of YK11 are completely based on what happened to some cells in a petri dish or test-tube.

This makes it near impossible to predict how effective it really is as a muscle-builder or what the optimal dosage might be.

YK11 Dosage

It’s important to understand that, without any data in living animals, it’s basically impossible to determine how much YK11 you need to take to elicit some kind of a profound muscle-building effect.

Anecdotal reports indicate people are taking anywhere from 5 to 20mg/day.

10mg/day seems like the average starting point.

It’s not clear what these doses are based on, though.  It seems like people are basing the dosage off of SARMs like Ostarine and Ligandrol.

But these SARMs have actually been studied in humans.

YK11 has not…

So dosage is really a guessing game with this stuff.

Anecdotal reports indicate that it’s effective at just a few mg/day, but many YK11 products are dosed quite a bit higher, in the 20-30mg range.

What Kind Of Results Can You Expect With YK11?

Here’s the thing…

Anecdotal reports indicate that YK11 is an effective muscle-building compound, but we have no solid research upon which to base our expectations.

To complicate matters further, a lot of people are stacking YK11 with SARMs like LGD-4033 and, in some cases, MK-77 (a GH-secretagogue).

In these types of situations, it’s basically impossible to tell how much YK11 is contributing to the overall result.

From what I’ve gathered, it looks like YK11, dosed between 10-30mg/day, can result in lean muscle gains in the high single-digits or low double-digits (8-12lbs maybe) over a period of several weeks.

High doses for longer periods of time could potentially result in greater gains, but again, we have no idea how safe it is.

Does YK11 Have Any Side Effects?

Out of all the compounds labeled as SARMs, including GW-501516 and Ibutamoren, YK11 has by far the least established safety profile.

It hasn’t even been studied in mice, so nobody really has any clue what the potential side effects are.

We can only speculate.

YK11 appears to cause suppression of natural Testosterone levels, meaning a solid post cycle therapy protocol is a good idea.

Due to the fact that it’s chemically a steroid, YK11 could also potentially cause things like:

  • acne
  • hair-loss
  • joint inflammation
  • high blood pressuure

Of course, side effects will vary from person to person, as is the case with any steroid.  If you’re genetically prone to things like hair-loss and acne, you may want to avoid YK11.

The real side effects you need to be aware of with YK11 is natural testosterone suppression.  At the very least, you should use an effective PCT supplement, if not a more powerful compound, like Nolvadex.

Is YK11 Legal?

This is where it gets a little complicated.

SARMs are legal to sell, not as dietary supplements, but as research chemicals.

They must be sold “for research purposes only” and “not for human consumption”.

But YK11 isn’t your typical SARM.  Chemically, it’s a steroid.

So does that make it a Schedule III substance like other anabolic steroids?  Who knows!?

Companies that sell SARMs will fight tooth and nail to maintain that YK11 is in fact a SARM and is therefore legal to buy, sell, and possess, but the government may decide it feels differently.

Right now, YK11 isn’t high profile enough to trigger any sort of legal response, but it’s certainly more likely to be targeted than SARMs like Ostarine or Ligandrol, simply because, chemically, it resembles a steroid.

It’s important to understand that this new wave of unapproved drugs–which includes SARMs as well as drugs like Cardarine and MK-677–represents uncharted territory as far as legality is concerned.

Until a government agency actually goes after a company or two that sells these substances and sets some sort of legal precedent, they will continue to operate in a gray market.

Fortunately, as a consumer, you’re very unlikely to get in any kind of legal trouble for buying or possessing YK11.

The DEA isn’t going to kick your door in for ordering a bottle or two, but the companies that currently sell YK11, claiming that it’s a perfectly legal SARM, may eventually see some legal action as a result.

Only time will tell!

Can Athletes Use YK11?

As is the case with all SARMs, YK11 is banned by the World Anti-Doping Agency (WADA).

If you’re a high level athlete who is subject to testing in accordance with WADA’s standards, than you probably shouldn’t use YK11.

If you’re not an athlete, it doesn’t matter what WADA says.

It’s not a regulatory organization.  It just sets standards for athletes which (obviously) only apply to athletes.

Where To Buy YK11

A quick google search yields various vendors of YK11 but, as is the case with all SARMs and gray market research chemicals, not all vendors provide a high quality product.

I wish I could point you in the direction of a vendor that I know to be trustworthy, but I’ve never actually tried YK11.

Ideally, you should go with a vendor who accepts credit cards.  That way, if anything goes wrong, you can dispute it with your credit card company.

Any vendor who accepts credit cards doesn’t want to risk getting a chargeback, so they’re more likely to provide quality products and decent customer service.

There seems to be a few vendors who offer a Certificate Of Analysis (COA), allegedly ‘proving’ that their YK11 is high quality and not contaminated or high in heavy metals.

I wouldn’t personally trust any companies COA, though, since most of those are provided by the manufacturer.  Obviously the manufacturer isn’t going to try selling YK11 with a COA that says it’s impure or contaminated.

Manufacturers force COA’s all the time!

Just something to keep in mind…

The Bottom Line On YK11

YK11 isn’t an ordinary SARM.  It’s actually a steroid.

It’s also EXTREMELY under-researched.  There are absolutely no studies in animals, let alone humans, so it’s unclear how effective it really is for building muscle, burning fat, etc.

Furthermore, there’s no established dosage, so people just seem to be making it up as they go along.

If you do decide to give YK11 a shot, be sure to let me know how it goes, but if you’re looking for a more effective, reliable compound that will build muscle rapidly while burning fat, check out some of the products on our Best Muscle Builders list.

By the way, I’m always down to talk supps, SARMs, or whatever!  You can find me on Instagram and Twitter.

Have anything to add about YK11?  Any Experience 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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