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YK-11 is more than just a SARM

YK-11 is more than just a SARM

YK-11 is possibly the most powerful selective androgen receptor modulator (SARM) currently on the market. It is also a somewhat unusual compound, which is different from SARMs like MK-2866, RAD-140, and Ligandrol (LGD-4033) in a few ways.

For instance, it is the only modern SARM which has a steroidal molecular structure. As a matter of fact, it closely resembles the structure of DHT (Dihydrotestosterone), a well known synthetic anabolic steroid.

Is YK 11 a SARM or a steroid?

Yk 11 molecular structure
Molecular structure of YK-11

The close resemblance to DHT on a molecular level has sparked debate on the question if YK-11 should actually be considered a SARM.

Some would argue it is actually a synthetic androgenic anabolic steroid.

There certainly is truth in both points of view, so it makes sense to describe YK-11 as a SARM/steroid hybrid.

How does YK-11 work?

Of all the SARMs currently on the market, YK11 has the least research data. There are no clinical data available to support the claims about the use of this compound and the associated side effects.

Most of what is known about the way that YK11 works, is based on the available research on a cellular level. Because of the popularity of this compound among bodybuilders, there is a fair amount of user reports.

YK-11 and selective tissue binding

Similar to other SARMs, YK11 binds to the androgen receptors in a tissue-selective manner. Because it binds to the androgen receptors in skeletal muscles it has strong anabolic properties, comparable to that of androgenic anabolic steroids.

YK-11 Myostatin inhibitor

Some of the basic research mentioned consisted of cellular testing in order to find out about the basic method of action. The results show that YK 11 simply aims to increase follistatin levels. Follistatin is another naturally occurring protein in the human body which helps keep myostatin in check.

When follistatin is raised, myostatin level is inhibited. Inhibition of myostatin results in increased muscle mass and improved strength.

The pros and cons of YK 11

So far, the only studies this SARM has seen are cellular ones. There have been no studies on humans or even on animals. Most of what we know about the benefits and side effects of YK-11 is based on anecdotal evidence and user reports.

This study shows that mice that have low levels of myostatin have twice the amount of muscle mass compared to mice that have high levels of myostatin.


Some of the benefits associated with the use of YK11 include:

  • Increased muscle growth
  • Improved fat loss
  • Increased strength

Increased muscle growth

The most obvious benefit of YK11 is without a doubt rapid muscle growth. YK11 is able to drastically improve muscle growth and produce new muscle cells. It does this by naturally increasing follistatin cells, whilst suppressing myostatin (a protein that stops excessive muscle growth).

Reports of 6 to 8 kg of increased muscle mass from an 8-week cycle are not uncommon.

Improves fat loss

Fat loss is one of the major advantages that YK-11 has to offer over most other SARMs and steroids. YK-11 focuses on replacing any excess fat mass with solid, strong muscle mass – one that you can be proud of.

Improve strength

The goal of YK-11 is not to pump your muscles but also to make them stronger. Through the production of follistatin, YK-11 works to strengthen your muscles, making them stronger than ever.

YK-11 SARM benefits - HQSARMS

YK-11 Side effects

Because there aren’t any studies on the safety of YK11 use in humans, we have to rely on user reports for info about the possible side effects of this SARM.

While most users report little to no side effects, others report quite a lot of unwanted side effects. The conclusion is that the side effects vary from person to person.

Some of the potentional side effects associated with the use of YK-11 are:

  • Testosterone suppression
  • Mild liver toxicity
  • Increased aggression
  • Joint and tendon pain

Most SARMs will lead to the suppression of natural testosterone production, and YK-11 is certainly not an exception in that regard. Despite the fact that it is the only SARM with a steroidal structure, the suppression is fairly limited compared to other SARMS, let alone anabolic steroids.

It is therefore highly recommended to use some sort of PCT after a cycle of YK 11 to restore testosterone levels. For more info about post cycle therapy after the use of SARMS, please read our article: A SARMs PCT: Do you really need it?

YK 11 vs RAD 140

As the title as this post already revealed, YK 11 is more then just a SARM. But how does it compare to – what is considered the strongest non-steroidal SARM: Testolone. We will provide a comparison based on several aspects.

YK 11 vs RAD 140 – half-life

When we look at the half-life of these two SARMs, RAD 140 vastly outperforms YK 11.

YK 11 has a half-life of just 12 hours, which means that it has to be taken twice a day to get the full benefits.

In contrast, RAD 140 has a half-life of 60 hours, so it can be used every other day without a significant drop in blood concentration level.

YK 11 vs RAD 140 – benefits

If we look at the results in terms of strength and muscle mass, YK 11 is without a doubt the stronger of these two SARMs. But when we focus on fat loss and vascularity, RAD 140 is without a doubt the most beneficial.

YK 11 vs RAD 140 – side effects

Where it concerns side effects, the most powerful compound usually has the most of them. And when comparing YK 11 with RAD 140 this is holds true:

  • YK 11 is more suppressive than RAD 140, which shouldn’t come as a surprise given the steroidal nature of this SARM.
  • Because YK 11 has a methylated group added to it, it puts more strain on the liver. With this compound, it doesn’t hurt to take some liver support such as Milk Thistle during the cycle.

YK-11 dosages

YK-11 is effective in dosages as low as 5mg per day. The most common dose for increasing muscle mass is 10mg per day, taken over a period of 6 to 8 weeks. Because YK 11 has a relatively short half-life of 12 hours, many users decide to divide the dose in two, taking 5mg in the morning and 5mg in the evening. Some bodybuilders will stack YK-11 with other SARMs like MK-677 or RAD140.

Where can I buy YK-11?

You can buy YK11 online here at HQSARMS in liquid form.

Frequently asked questions

Is YK11 legal?

At this moment, YK-11 is legal in almost every country around the world, with the exception of Australia. However, as it is not approved for human consumption, it cannot be sold as a supplement in most countries. But it can be sold for research purposes.

What is the half-life of YK11?

The half-life of this substance is relatively short: somewhere between 6 and 10 hours. Therefore, it is usually divided into several portions during the day.

Does YK11 cause hair loss?

Unfortunally, there have not been any human studies on the use of YK11, so there isn’t much info about the side effects. There are however cases where users complained about hair-loss.


To summarize, YK-11 is a steroidal SARM that is closely related to DHT, which is a powerfull synthentic steroid. It is also a potent myostatin inhibitor that is able to rapidly increase muscle growth and strength.

While it isn’t approved for human consumption by the FDA, it is used a lot by body builders because of the strong performance enhancing effects it has.