YK-11 (Myostatin Inhibitor) SARM – Uses, Side Effects and More

If you’re familiar with SARMs, you might think YK11 is just another SARM that is useful for bodybuilders. But YK-11 is like no other SARM. It is a little different in the way it works, and when it comes to potential results (which, let’s face it, is what we’re interested in), YK-11 can be placed near or even at the top of the pile of SARMs for muscle growth. Some even call it the most potent SARM, and while that’s impossible to prove, there’s no doubt that YK11 is very effective and, therefore, should be a top consideration if you’re looking to get into SARMs or try a new compound.

Before you even consider using this SARM, you will want a perfect understanding of what it does and how it does it. Throwing YK-11 into a cycle or stack without knowing its primary purpose will only lead to disappointment and some hideous side effects. But wait, let me tell you something: You will come across a lot of negative commentary about YK-11 because this is a SARM that divides the bodybuilding community for several reasons. I’m not here to tell you whether or not you should use it. What I will do is present all the facts and all the critical things you need to know about YK-11. The rest is up to you. Now, let’s get into it!

Medical disclaimer: The following guide is based on personal experience and does NOT promote the illegal use of steroids (PEDs). Consult a healthcare professional before using PEDs.

What is YK-11?

YK-11 is a steroidal selective androgen receptor modulator (SARM), differentiating it from most modern-day SARMs in bodybuilding and performance. But why is that? The majority of new SARMs are now non-steroidal. YK11 is also one of the least tested SARMs, so we have hardly any data at all to go by in terms of both its measured positive effects and its short and long-term side effects. There are exactly ZERO studies or trials of either animals or humans with YK-11.

But as always, we have plenty of anecdotal and personal experiences from individuals in the bodybuilding community. These cover the spectrum of good and bad experiences and everything in between. We know that YK11 is excellent for making mass gains, can assist with fat loss, and helps shape the physique with no fluid retention. For these reasons, it appeals to bulking and cutting goals while also being a compound that females can use.

A Quick Look at YK-11

• Other Names: YK-11 (generic).
• Primary Use: Research chemical studied for muscle hypertrophy. Off-label use for extreme muscle growth and fat loss in bodybuilding. Not approved for human use.
• Administration: Oral form (research chemical, not standardized for human use). Typical Dosage: 5-10 mg/day (split into 2 doses due to short half-life).
• Cycle Length: 6-8 weeks (limited data on safety). Often paired with SARMs (e.g., RAD-140) or steroids (e.g., testosterone) to amplify muscle growth.
• Benefits: Extreme muscle hypertrophy (via myostatin inhibition); enhanced fat loss and strength gains; no estrogenic side effects (does not aromatize).
• Side Effects: Severe testosterone suppression (HPTA shutdown); joint/tendon pain (myostatin inhibition may weaken connective tissue); liver toxicity (hepatotoxic due to C17-alpha alkylation); cholesterol imbalance (increased LDL, reduced HDL); organ enlargement (heart, kidneys); long-term myostatin suppression.

Note: YK-11 is highly experimental and risky, with no human clinical trials to validate safety or efficacy. Its myostatin-blocking effects could lead to irreversible health issues, including weakened tendons and cardiovascular strain. Not recommended for use due to extreme unknowns and potential for severe side effects.

YK-11 history and Overview

As a steroidal SARM, YK-11 is what we’d call one of the “old school” SARMs. Steroidal SARMs have been of interest in research since the 1940s^[1]. These mainly were modified testosterone hormones. Only in the 1990s did development and research on nonsteroidal SARMs start to take off, thanks to work by Ligand Pharmaceuticals.

YK-11 is based on the Nandrolone hormone, which is one you’ll be familiar with if you’ve ever used or had an interest in anabolic steroids. This essentially makes it a 19-nor steroid. And if that’s not enough… While it is still a SARM, you will see YK-11 also being called a myostatin inhibitor. As a protein that will hamper muscle growth, inhibiting myostatin is desirable for gaining muscle and doing so at a high rate and quickly.

Unfortunately, YK-11 is no longer in research, falling out of favor with more modern nonsteroidal SARMs. There’s also no data from any studies besides those on cells, making this one of the more mysterious SARMs, at least in terms of official scientific results.

Mechanism of Action

YK-11 helps remove a limitation to building muscle: Myostatin. Myostatin is a protein found exclusively in the skeletal muscle and is known to inhibit muscle growth. YK-11 can inhibit myostatin, removing this natural barrier to more muscular growth. This makes YK-11 a PED that won’t directly stimulate much muscle growth on its own. This is why YK-11 is often used with SARMs that facilitate direct muscle growth, allowing YK-11 to remove limitations and make more significant gains (myostatin).

Effects of YK-11 (Benefits)

YK-11 is a true performance SARM and one that appeals to some steroid users. For that precise reason, people who prefer only to use SARMs (and not steroids) will often choose never to use YK-11 at all because of its potency. But for those who do, some potent effects can be experienced. And most of these will only be realized at their full potential when you’re using injectable YK-11.

YK-11 promotes muscle growth by increasing the development of a critical muscle-building protein called follistatin. At the same time, it has also been shown to stimulate the proteins that build bones, which is one of the properties we see with many SARMs and why they are being seriously researched to treat osteoporosis.

These effects can increase bone density and lean muscle gains, which are highly desirable for bodybuilders and elite athletes. But so far, only cellular and some animal studies have been done on YK-11, and its benefit for humans at higher doses is anecdotal based on personal experiences.

It’s not uncommon to hear about gains of up to 15 pounds within one single cycle of YK-11, while fat reduction during this time can also be significant. This can make YK-11 useful not only for bulking up but for cutting phases as well. YK-11 can help retain muscle tissue during cutting and stimulate its growth if the diet supports it.

Here are the main benefits and effects of YK-11:

Muscle mass gains

YK-11 will stimulate the production of muscle cells and can support some nice muscle gains when used on its own. Still, when it’s stacked with any other PEDs (as it often is), it’s going to boost their anabolic effects substantially as well due to the inhibition of myostatin. This can make it difficult to know how much muscle can be gained with YK-11 alone (remembering that we have zero clinical studies). Consider that many have gained at least 10 lbs of quality muscle on an 8-week cycle, and you begin to see the power of this SARM. Stacked cycles with RAD-140, for example, can see you gaining up to 20 lbs in body weight.

Dry and hard gains

YK-11 will dry out your physique and increase muscular hardness. Often called a “3-D appearance” – very defined, blown up muscles with no water retention. Two steroids I usually compare YK-11 to are Winstrol and Masteron, so if you’re familiar with what those can do to the physique, you’ll understand how YK-11 can deliver in this area of effects.

Pumps

Many users will discuss super-powerful pumps with YK-11 and general muscle fullness. Pumps can be intense; the higher your dose, the more you can expect your pumps to ramp up. This is one of the most confronting and noticeable effects of YK-11 and will be even more pronounced when stacked with something like RAD-140.

More strength

YK-11 will give you a massive strength boost. This is one of the effects you’ll hear users raving about the most. Something that can and will reduce your strength gains on a YK-11 cycle, though, is testosterone suppression, so you should prioritize controlling suppression if you want to maximize strength gains. Your lifting ability will improve noticeably throughout the cycle, allowing you to break through personal bests and plateaus.

Faster recovery

YK-11 is known to speed up recovery even better than any other SARM. This means less muscle soreness after working out and the ability to work out the same muscle groups with less downtime between sessions.

Increase bone strength

We know that SARMs bind to androgen receptors in the bones, which can stimulate an improvement in bone mineral density, ultimately improving the bones’ strength and health. Strong and healthy bones provide the structure to lift heavier and support your increased muscle growth.

Fat loss

There are other SARMs with more fat loss ability than YK11. Still, there’s no doubt this one will also boost fat burning, particularly as you’re gaining lean muscle, so your metabolism will naturally become more efficient. More muscle equals faster fat burning, which means the metabolism keeps working to burn off fat even while you’re resting.

YK-11 Dosing and Administration

The way you dose and administer YK-11 is going to depend on what your preferred form of this SARM is:

• Liquid
• Injection
• Capsules

The low oral bioavailability of YK-11 compared to other SARMs makes this one not at its best when taken orally (liquid or capsule). You’ll get better results and possibly fewer side effects by injecting YK-11 at low doses compared to high-dose sublingual administration.

Doses

Doses of YK-11 will depend on whether you’re taking the liquid oral solution or have decided to do YK-11 injections. This is very important: Injectable YK-11 requires a lower dose than oral. An oral starting dose will usually be around the 10mg daily mark, but 10mg is quite a high dose for injecting YK-11. The dosages below are based on injecting YK-11, as this method will provide the very best effects and results with this SARM:

Beginner

5mg is a solid introduction to YK-11 and lets you get a feel for its positive and negative effects without going overboard. Joint pain should be minimal at this dose, but suppression is still an issue and will require PCT and, ideally, on-cycle support.

Intermediate

10mg daily taken 5mg morning/night. This dose will noticeably improve your strength gains and likely crash your testosterone. If you weren’t already using a testosterone or SERM base on-cycle at 5mg (recommended), you’d certainly need it at 10mg. Muscle hardness will be impressive at this level, and you should start experiencing some big pumps.

Advanced

The most advanced users are known to inject 15mg daily (if taken orally: 30mg). At this dosage, testosterone shutdown is likely, and you will also be looking at stacking YK-11 to take advantage of the myostatin-inhibiting effects to boost the lean mass gains of other compounds rather than relying on excessive doses of YK-11.

Female

YK-11 use is rarely reported by females as other SARMs are better suited to female athletes. Women who want to attempt using YK-11 should do so at the lowest dosage range, 0.5mg to 2mg, to evaluate their response and side effects.

Bioavailability, half-life, and cycle length

Although we have no human (or animal) studies to back this up, it has become well-known that YK-11 has poor bioavailability when taken orally (the way almost everyone takes most other liquid or capsule SARMs). So, what does this mean in the real world? This means it isn’t absorbed and used by the body efficiently. If you take oral YK-11, your dose will need to be higher than if you’re injecting. Many YK-11 users inject it at a low dose of 5mg to 10mg daily and see excellent results.

The half-life of YK-11 is still up for debate. Suggestions of anywhere from 4 to 12 hours are common – because no one knows. But get this: 4-8 weeks is the recommended length of use of YK-11, which applies if included as part of a stack. Plenty of guys will want to stop at the 4 to 6-week mark because this is such an intense SARM to use, and going to 8 weeks is not always necessary or desirable if you’re finding the side effects difficult to deal with.

Dosing schedule and administration methods

I’m sure you’ve noticed that almost all SARM users take their dose orally using a liquid product. YK-11 is, again, a little different. Yes, it can be bought as a liquid like any other SARM. However, many will argue that due to YK-11’s very low bioavailability when taken orally, it’s not even worth taking it that way. That leaves one other option to boost bioavailability: Injecting. But for a lot of SARM users, the big appeal is NOT having to inject, making it one of the leading reasons SARMs are often chosen over steroids.

OK, I know what you’re thinking: Should I bother using YK-11 at all if I don’t want to inject? Many still take it orally, but as I’ve mentioned, you will usually need a higher dose to see worthwhile results. Now, this is a critical thing to know if you’re going down the injecting path: Don’t just inject liquid YK-11 from the bottle of regular SARMs. You will need to buy the specific injectable form of YK-11, which is formulated to inject by placing the YK-11 into a carrier solution such as MCT oil. Administration of YK-11 injections should be the same as anabolic steroids, with all hygiene precautions taken.

Taking YK-11 at least twice daily is the best approach, given its half-life is likely under 12 hours. Many will take it as a pre-workout and find it provides a noticeable boost to strength and performance.

YK-11 Cycles

Anyone with PED experience will tell you very clearly: If you’re going to use YK-11, you should think of it as a steroid, which means running a testosterone base. Now, that will turn away anyone who isn’t keen on injecting anabolic steroids (a lot of SARM users).

So, can you stack YK-11 without a testosterone base? Yes, but prepare yourself for the inevitable suppression that will occur. Alternatively, we can use Nolvadex or Clomid in place of a testosterone base. This is the option most users take, and it can effectively support the high-level suppression caused by YK-11.

YK-11 cycle for men

What you read and hear from men who run a YK-11 cycle can vary from the mediocre and unenthusiastic right up to the guys who will swear that YK-11 is as powerful as some steroids.

Why the difference in experiences?

The main reason is that oral YK-11 has such low bioavailability that it’s rarely going to be able to support the same level of results that you can get when injecting YK-11 (not everyone is aware of this).

Then there are the common complaints of joint pain that some, but not all, users will suffer with at some point on a YK-11 cycle. At a 15mg dosage for eight weeks, men will typically find that side effects like joint pain are minimized while effects are still exceptional.

Results to expect include:

• A hard, dry physique
• Muscle gains of up to 15lbs (potentially more)
• Loss of body fat in the 5-10% range, depending on your current body fat levels.
• Strength through the roof

Positive comments and reviews from men on YK-11 cycles always focus on the strength gains and the muscle hardness, and many will mention intense pumps. But the negatives will also go down that same road: With similar effects to steroids come similar potent side effects.

There are also more than a few other negative comments out there about a range of bad experiences with YK-11:

• Issues caused by suppression, like low energy, when measures aren’t taken to provide testosterone support.
• Depression and other mental issues (which also might or might not result from failing to maintain testosterone levels).
• Aggression and irritability.
• Some guys complain that YK-11 doesn’t do much; almost certainly, they are taking it sublingually and experiencing its poor oral bioavailability.

Reviews and comments about YK-11 often compare it to steroids. Guys who have a history of steroid use don’t shy away from stating that YK-11 is as powerful or even more so than steroids like testosterone taken at performance doses. That tells all we need to know about how incredibly powerful YK-11 is!

YK-11 cycle for women

Due to its steroid-like effects, YK-11 is not known to be used by women very often. There are FAR more appropriate and better-tolerated SARMs (and even steroids) for women, so a female would need a very good reason to want to use YK-11. Females can expect results similar to those of men who use YK-11: Increased strength and muscle gains, faster recovery, and some fat loss.

Females will require a very low dose of YK-11 to experience its effects: As low as 0.5mg daily may help avoid the worst side effects. However, with so few anecdotal experiences being shared, women may suffer from side effects that we aren’t expecting from this SARM. Due to the lack of known use of YK-11 among females, very few anecdotal experiences are available of either positive or negative experiences from women who have run a YK-11 cycle.

YK11-only cycle

YK-11 is a SARM that is more than powerful enough to use on its own with excellent results, and that is what many people do. The shortest and sharpest introduction cycle is to take just 5mg daily over a 4 to 6-week cycle. New users of YK11 can use this short cycle to evaluate results, and you will see results within that short time frame while minimizing testosterone suppression. Once you feel more confident, you can consider increasing the dosage to 10 or 15mg daily for an 8-week cycle. Note that a dose of any higher than 15mg is not recommended.

YK11 bulking cycle

YK11 will bulk you up seriously when used on its own, but if you want to take things to another level, there are some other SARMs and similar compounds you can stack it with. One of the common ones to use with YK-11 is LGD-4033 (Ligandrol). Super advanced users might even add a third compound, with Testolone (RAD-140) and Ostarine (MK-2866) being popular.

However, the most powerful bulking and strength combo is possibly the YK11 stacked with RAD140. This emphasis on boosting strength is essential because this extra strength will power your workouts and bring on those bulking results much faster. Gains will also be nice and dry without issues of water retention. Dosages in this 8-week cycle can be set at 10mg daily for YK11 and 15mg daily for RAD-140. These doses will give you noticeable strength benefits within just the first week.

YK11 cutting cycle

S4 (Andarine) and Cardarine are compounds that provide an exceptional cutting cycle when stacked with YK11. If you only choose one compound to stack with YK-11, which is the best strategy, consider Cardarine. While it’s not strictly a SARM, it is a popular cutting compound and is very effective for stimulating fat burning.

At low doses, Cardarine is effective and boosts endurance, propelling your workouts for quicker fat-burning. 10mg/day of Cardarine combined with just 5mg/day of YK-11 will promote muscle retention, possible muscle gains, and, importantly, fat loss and physique hardening without water retention or gyno.

YK-11 vs. Other PEDs

YK-11 differs from many other SARMs we are familiar with as it is a steroidal SARM. Non-steroidal SARMs are relatively new, but the first steroidal SARMs were developed in the 1940s. As a steroidal SARM, YK11 was developed by modifying DHT (Dihydrotestosterone), an androgen hormone.

So even though it’s more similar to steroids than other SARMs and gives you some similar results to steroids, although rarely as extreme when it comes to muscle gains, YK-11 should not be confused with a steroid. It gives you some steroid benefits without the most serious downsides and side effects.

Compared with other SARMs, YK-11 has its share of side effects that are not always apparent with other SARMs. Many others won’t, for example, cause the potential hair loss that YK-11 can. Again, this is due to this SARM’s modification of DHT, which is not an issue with non-steroidal SARMs.

All in all, YK-11 is about as close as you can get to a steroid cycle without it being one, so it sits in the middle of anabolic steroids and most other SARMs used for performance enhancement.

As a powerful bulking SARM, it makes sense to compare YK-11 to other SARMs primarily used for gaining muscle (although many also have other additional benefits). So, I want to briefly compare YK-11 to two SARMs that people often ask about comparing benefits and results.

YK-11 vs. RAD-140

There are plenty of reports of guys stacking these two powerful SARMs. Just be aware that this will result in almost or total testosterone shutdown (among other things).

But what if you want to put YK-11 and RAD-140 side by side and decide which ONE to use? Here are the main points of similarity and difference between RAD-140 and YK-11:

• RAD-140 is a nonsteroidal SARM, while YK-11 is steroidal.
• Both are suppressive, with YK-11 being more suppressive than RAD-140.
• Both will promote muscle gains, but RAD-140 does it directly and much more powerfully.
• Both will boost muscle growth, strength, bone density, and recovery.
• Both can impact liver and cholesterol values.
• RAD-140 is known to cause hair shedding, much more so than YK-11.
• Both are dry compounds with no water retention.
• RAD-140 is versatile enough for bulking, cutting, and recomp cycles, but YK-11 is primarily used in bulking and strength cycles.

These two very different PEDs have differing mechanisms of action, resulting in entirely different ways of building muscle and other effects.

YK-11 vs. LGD-4033

These two bulking cycle candidates are powerful but go about things very differently.

Purely from a muscle-building and aesthetic perspective, LGD-4033’s water retention provides additional challenges if you’re looking for a hard, toned physique. Still, with the right approach, this can be managed well.

• Both will suppress testosterone.
• LGD-4033 has a longer half-life and can be taken once daily.
• YK-11 is the better strength booster.
• LGD-4033 users typically find recovery times superior to YK-11.
• LGD-4033 is thought to pose less of a risk to the liver.

In short, LGD-4033 is a bulking SARM, while YK-11 can be thought of more as a strength SARM when used on its own. The real power and skill are found in combining these two in a stack and reaping their benefits.

Stacking YK-11

Stacking YK-11 is the best way to use it because it will be a booster for the muscle-building effects of the other PEDs in the stack. How does it do this? By inhibiting the protein myostatin. So, there’s an excellent opportunity for synergy when combining YK-11 with powerful bulking SARMs like RAD-140.

YK-11 + RAD-140 (bulking stack)

This is the most common YK-11 stack you’ll see talked about. It’s a hardcore bulking and strength stack with two of the most potent SARMs. In other words? Not for beginners! Get a good amount of experience with both before even considering running this stack.

Benefits

• Big strength increase
• Huge lean muscle gains
• Big pumps
• Dry, hard, and vascular
• Increased aggression (many see this as a positive)
• Fast recovery times

Dosing

• YK-11: 10mg daily
• RAD-140: 10mg daily
• Recommended: 10-20mg of Nolvadex daily on cycle to combat suppression.
• Cycle length: 8 weeks

Possible Side Effects

• Testosterone suppression
• Liver and cholesterol stress
• Joint pain
• Hair shedding

Results

With both these SARMs being dry compounds, you won’t be weighed down with water retention. Muscle gains of 15lbs+ will be lean gains and should be well maintained after your cycle IF you ensure actions are taken to maintain testosterone levels both during and after the cycle.

PCT

30mg/day Nolvadex for three weeks, then 15mg/day for the final 4th week.

YK-11 + Stenabolic (recomp stack)

I want to go against the grain a little here and move away from pure bulking stacks to what we could call more of a recomp stack with the addition of Stenabolic. Stenabolic is not a SARM but a Rev-ErbA agonist, so these two compounds have very different mechanisms of action without overlap. Just like YK-11, Stenabolic has low oral bioavailability, and many users will instead choose to inject it.

Benefits

• Increased endurance
• Cholesterol support from Stenabolic
• Fat loss
• Some dry lean gains
• Dry and lean physique with increased definition
• Muscle preservation if you’re in a calorie deficit
• Strength maintenance

Dosing

• YK-11: 10mg daily
• Stenabolic: 20-30mg daily
• Cycle length: 8 weeks

Possible Side Effects

• Testosterone suppression
• Possible liver stress
• Insomnia

Results

A complete body recomp is possible in just eight weeks on this cycle. With Stenabolic boosting endurance and YK-11 supporting your strength and muscle preservation, this underrated combination provides impressive body transformation. The main downsides are the short half-life and multiple daily injections of both these PEDs; ideally, YK-11 should be administered twice daily and Stenabolic up to three times daily.

PCT

Four weeks of Nolvadex: 40mg/daily for the first two weeks, 30mg/daily for week 3, and 20mg/daily for week 4.

YK-11 + MK-677 (bulking stack)

This is also a stack focused on bulking (because YK-11 is best at making it easier to gain muscle above all else). MK-677 will boost your appetite and make it possible to eat the calories you need to get the gains you aim for.

Benefits

• Significant muscle gain
• Increased appetite
• Great pumps
• Big strength
• Fast recovery
• Improved sleep quality

Dosing

• Weeks 1-8: YK-11 10mg/day, MK-677 25mg/day
• Weeks 9-12: MK-677 25mg/day
• Weeks 9-10: Nolvadex 40mg/day
• Weeks 11-12: Nolvadex 20mg/day
• Cycle length: 12 weeks

Possible Side Effects

• YK-11 is a dry compound, but MK-677 can cause some water retention.
• YK-11 is suppressive, so PCT is required (see below).
• Possible increase in blood sugar levels.

Results

Muscle gains of up to 15 lbs are possible. YK-11 will help offset some of the water retention of MK-677, but you can also reduce it further by minimizing sodium in your diet and drinking plenty of water. Significant gains in strength can be expected, and you can break through personal bests lifting weights.

PCT

We continue using MK-677 for an extra four weeks due to its benefit of acting as PCT support. A Nolvadex PCT should also be run because while MK-677 isn’t suppressive, YK-11 will cause significant suppression.

YK-11 PCT

Do you need to do post-cycle therapy after using YK11? Yes, it’s always ideal to have your PCT ready to go. You can expect some suppression of testosterone with this SARM, ranging from mild to moderate, depending on your dose. Thinking about PCT from the start of your YK-11 cycle would be best. And I don’t just mean the “post cycle” part of PCT because you’ll almost always want testosterone support on cycle as well when using this suppressive SARM.

If you’ve used steroids before, then you can expect YK-11 not to cause a testosterone crash or complete suppression, but you should not go into using YK11 thinking it’ll have zero effect on testosterone; virtually all SARMs suppress to some extent. Stacking YK-11 with another suppressive PED? Don’t even think about not using a testosterone or SERM base for support on-cycle. If you’re stacking YK11 with one or more other compounds, you can expect more suppression, but again, this depends on doses and cycle lengths.

Standard PCT protocols can be followed, with the length of PCT unlikely to require being as long as you’d complete after steroids. A minimum of 4 weeks is still recommended. The most commonly used PCT drugs will be highly effective after a YK11 cycle, with those being Clomid and Nolvadex. It’s highly unlikely you would need to take PCT further by using HCG, which is common after steroids.

Signs of lowered testosterone include lack of energy, loss of muscle, fat gain, low libido, and general feelings of being unwell. It’s best not to wait for these signs to occur and instead to be proactive in getting PCT going after your YK-11 cycle. So, for your entire YK-11 cycle, I recommended taking either of the following:

• Enclomiphene at 12.5mg daily, or
• Clomid at 25mg daily, or
• Nolvadex at 10mg daily

This will ensure you don’t fall into a debilitating state of low testosterone while on cycle. Continue with your chosen SERM for the actual PCT for another four weeks at the end of your cycle.

YK-11 Side Effects

Many like to consider SARMs side effect-free, but this is rarely true. YK11 certainly comes with fewer side effects compared to anabolic steroids, but there are still going to be things to watch out for. Most importantly, this SARM has no research or studies to confirm adverse effects, so what we know comes from those who have been using YK-11 and have recorded and shared their own experiences. This means there could be negative impacts that are still not widely known; for this reason, it’s always wise to begin YK11 at low doses until you know how it affects you.

YK-11 has not shown any evidence that it can raise estrogen levels, and users report no water retention. So, we can expect no estrogen-related side effects from this compound. This means no bloating and no gyno to deal with. We know that androgenic effects are a mild possibility, but not to the most extreme extent compared with steroids. YK-11 is a potent compound, so you can expect to be dealing with some pretty harsh side effects (especially if taking higher doses above 5mg daily), such as:

• Testosterone suppression
• Joint pain and stiffness
• Liver issues
• Hair loss
• Negative cholesterol changes

Other side effects that are often reported anecdotally (and not necessarily experienced by all YK-11 users) include increased aggression, acne, and insomnia.

Testosterone suppression

Suppression on YK-11 can range from moderate to severe or even total shutdown. Stacking with any other suppressive compound will likely result in a complete shutdown, particularly with issues like fatigue and potentially losing some muscle gains and gaining fat after your cycle. This is a clear sign of low testosterone, so to avoid these negative impacts, it’s wise to have PCT ready to go following your YK11 cycle, both from a health perspective and to retain the gains you’ve worked so hard for. Most men will want to run a testosterone base with YK-11, but this could also mean just using a SERM like Nolvadex throughout the cycle.

Joint pain and stiffness

The next most common side effect being reported relates to the development of pain in the joints. It’s not known exactly why this happens. Still, it possibly relates to YK11’s effect on the regulation of cortisol, which is a function of DHT itself and is why DHT-derived steroids like Winstrol are also known for causing joint pain.

Myostatin inhibition can also cause stiffening and joint pain, which can impede your strength as you begin to have difficulty with a full range of movement. The type of pain can vary. Some users have noted a sudden onset of sharp pain in places like the knees, while others report ongoing low-intensity pain in various joints. Some users will find joint pain worsens as early as the first week of a YK11 cycle. This can include just about any joint in the body: Elbows, knees, shoulders, and even the fingers. Lowering the dosage to 5mg can help reduce joint-related side effects.

Liver

Then there’s the issue of liver toxicity. There is not enough evidence either way that YK-11 can damage the liver. Still, there is certainly the possibility of liver stress occurring, especially at higher doses, with YK-11 being a compound that most people take orally. Both oral and injectable YK-11 can potentially stress the liver. The injectable form is thought to be less toxic to the liver, but we lack any scientific evidence of how much stress YK-11 places on the liver. This is another good reason to keep up with your bloodwork before, during, and after your cycle.

If you have a pre-existing liver condition, it’s wise to be very careful with your YK11 doses. Liver support supplements can provide some protection, but if you’re especially concerned about the impact on the liver, blood tests can be performed to note any changes in the liver. In any case, on-cycle liver support (such as NAC and milk thistle) is highly recommended.

Hair loss and acne

There can be some mild androgenic-related effects in some users of YK11, and one of those is hair loss, a side effect that will be familiar to users of steroids. Acne is another androgenic effect that some people might experience, but this is usually mild compared to the severe acne that can sometimes occur with steroids.

Hair shedding or loss is a side effect that is heavily individualized. Some users will see no issue, but others have noted severe hair shedding. You won’t know whether you’re affected by hair loss with YK-11 until you start using it. Interestingly, some guys who have tried both oral and injectable forms of YK-11 have noted that the oral form causes MUCH more hair shedding. In contrast, minimal hair loss was experienced when injecting YK-11.

Just like with steroids, these impacts will mostly only affect people who are genetically predisposed to either baldness or acne, and most guys aren’t going to see these issues popping up unless you’re using very high doses of YK11 (which is not recommended for numerous reasons).

Cholesterol

YK-11 will cause some negative cholesterol changes to LDL and HDL levels. You’ll need bloodwork to confirm how serious this side effect is, especially as you’re unlikely to feel any different even with significantly elevated cholesterol levels.

Aggression

This could be the most talked about side effect of this SARM, and it brings to mind the issue of “roid rage,” which steroids are notorious for (although not always accurately). A potential increase in aggressive tendencies can come about because of alterations to the balance of hormones, which can impact mood.

Some users note this is more noticeable when things start kicking in at the start of the cycle. Those who are already prone to bad moods or are quick to anger are going to be at higher risk of having that personality trait worsened when using YK11, especially at higher doses.

To minimize this potentially serious side effect, which can have repercussions not only on yourself but also on other people around you, lower your YK-11 dosage to a point where aggression management is made possible. For many YK11 users, this can become the most concerning side effect rather than any physical effects.

YK-11 Results

Several factors will contribute to your results with YK11: Your dosage, the length of your cycle, any other compounds you might stack it with, your diet, your workouts, and your current physique and fitness level. That’s a lot of variables to consider. Still, this SARM is most likely to appeal to guys already heavily into bodybuilding, so they have a solid idea of the work that needs to be put into the gym and the diet to achieve results.

With this in mind, you can expect to see superb gains even on the lowest doses of YK11 and short cycles, so those just starting can still look forward to fantastic results, such as gaining up to 5 pounds of quality muscle and losing a percentage or two of body fat during a cycle of just four weeks taking only 5mg daily.

If you want to take things further, you can potentially match some of the bigger gains people are making on longer cycles of 8 weeks at 10-15mg daily, in the real case of up to 15 pounds of solid muscle gained. This is right into anabolic steroid territory and shows us just how powerful the YK-11 SARM is, as results like that are difficult to come by with the majority of other SARMs.

Users of YK11 often note that it starts working quickly, with some people noticing gains in as little as one week. For most users, you will be looking to evaluate your results over the entire cycle with a realistic expectation that high-quality and sustainable gains will reward those who stick with YK-11 and a quality workout regime for 6 or 8 weeks.

In addition to mass gains, you should notice a loss of fat and an increasingly defined physique by the halfway point in a cycle. If cutting is your goal, you’ll be on a calorie-deficit diet, and your fat loss will be more substantial. The physique will also be hard and dry because this compound doesn’t cause fluid retention.

Where to Buy YK-11?

Buying YK-11 is something most of us find very easy to do online. Where you live (country) will affect how much you pay and if there are any complications in ordering SARMs. For most countries, including the US, it’s a stress-free process.

Availability of YK-11

Even though YK-11 is based on a steroid and acts much like a steroid, it’s still a SARM and is easily purchased via the usual SARM suppliers where you’d buy nonsteroidal SARMs. So you won’t have issues finding YK-11 via the same methods you might have used to buy RAD-140 or any other popular SARM.

If you’re planning to inject YK-11, you’ll need to look specifically for injectable YK-11 products. Few suppliers sell injectable SARMs, as most people still prefer to take liquid. Capsule YK-11 is also sold. Whichever type of YK-11 you prefer, online availability is widespread and accessible.

Is YK-11 legal?

Even though YK-11 is so closely related to steroids, it’s still categorized as a SARM, and so it falls under the same research chemical class as all the other SARMs you know and love. This makes it easy to buy and use as a bodybuilder for personal use.

Online research chemical sellers are legally allowed to sell their products as long as they’re sold with the disclaimer that the SARM is for research purposes only. Should you be worried about this? What if you’re not a researcher? Most of us aren’t researchers (besides “researching” our strength and muscle gains).

But don’t worry: For now, no authorities are checking who is using SARMs and why, so they don’t come with the legal worries that we have when buying and using anabolic steroids.

But what about if you’re a competitor or professional athlete? YK-11 is classified as a prohibited drug by WADA and all sporting authorities around the world. It’s considered a performance-enhancing drug like anabolic steroids are, and drug testing will target the use of all SARMs.

Typical pricing

You should be able to find YK-11 at prices similar to those of most other SARMs. Liquid, injectable, and capsules are available from all the top online research chemical sellers. You can also find YK-11 powder, although few of us will go down that path due to the complications in measuring out accurate doses and administering powder.

• Liquid YK-11 typically comes in a 30ml bottle, dosed at 10mg/ml concentration. Expect to pay around $60 per bottle.
• Injectable YK-11, where the solution is suspended in a carrier oil ready for injecting, typically comes in 10ml vials priced between $60 and $100.
• Bottles of 60x5mg YK-11 capsules can be found for around $60.

Most sellers provide an online certificate of analysis, showing lab results from a third-party testing company certifying the purity of the formula.

FAQs

Is YK11 a steroid?

YK11 is not an anabolic steroid, but it is a steroidal SARM, which means it has been created based on a steroid hormone – in this case, it is DHT. This makes it more like a real steroid compared to the most modern SARMs, which are non-steroidal. The difference between this SARM and real steroids is that YK-11 still only has selective targeting of androgen receptors, mostly in the bones and muscles.

Is YK 11 a SARM?

Yes, YK11 is a SARM (selective androgen receptor modulator). It is an older type of SARM known as a steroidal SARM, while the newer SARMs being developed today are mostly non-steroidal. They all still work to target specific androgen receptors in the muscles and bones, making YK11 effective for muscle growth and improving bone strength.

What is YK 11 used for?

YK11 is used for muscle-building, which is bodybuilders’ primary goal. It has no medical uses and is only in the early stages of research, so there is still much to learn about it. The other significant benefit of YK11 is its ability to promote bone strength by increasing mineral density. It might also help with fat loss, although it is not considered primarily a fat-burning SARM.

Is YK11 dangerous?

Any substance has the potential to be dangerous when used outside a medical setting and at higher doses for performance enhancement purposes, and this is even more so for a compound like YK11, which is purely a research chemical at this time and has had no studies at all undertaken on it. This means that you use YK11 at your own risk and always be aware that you could experience complications or adverse effects that are unknown or unexpected. To play it safest, never exceed the highest recommended dose of YK-11.

Do you need PCT after YK11?

YK11 can cause some suppression of testosterone, but the level of this is unlikely to be near that of steroids. Most guys can expect some drop in testosterone levels even at the lower dose of 5mg, and the longer your cycle, the more suppression you will experience and the greater the need for PCT will be. All users of YK11 should have a PCT plan and be ready to implement it for at least three or four weeks.

Will YK11 show up on a drug test?

All SARMs are prohibited in competitive sports, and many athletes have been caught through drug testing with SARMs in their system, and YK11 is no different in this regard. Not enough is known about YK11 to know how long it stays in the system and how much needs to be present to show up in drug testing; therefore, if you’re a competitor using YK11, then this is a risk that needs to be considered.

Does YK11 cause hair loss?

YK11 can potentially cause hair loss or male pattern baldness in some men predisposed to this condition. The androgenic activity that causes hair loss isn’t as strong in YK-11 as in steroids; not everyone will experience this side effect. Still, it is possible, and the risk increases as you raise your YK-11 dosage.

Does YK11 increase testosterone?

Even though YK-11 has been created based on DHT, it still doesn’t impact hormones in the same way that anabolic steroids do. YK11 doesn’t boost testosterone levels to promote anabolic activity; instead, it targets certain androgen receptors in the muscles and increases the anabolic activity in those areas.

What should I stack with YK-11?

YK-11 is going to give you outstanding results when used on its own. For many users, this will be enough. However, for more confident and advanced users, you might consider stacking it with other compounds, and YK11 is compatible with stacking with other SARMs. Still, it’s not a recommended strategy for beginners. Once you start stacking, the dosage of YK11 is mainly recommended to stay at the 5mg daily limit because you will have to deal with additional side effects from the other SARMs or compounds you’re using. You can stack YK-11 with almost any SARM, with some of the best choices being RAD140, LGD-4033, and Andarine.

Final Thoughts

YK-11 is known as a very potent SARM, even though it is quite new, and we are still in the learning phase of knowing exactly what it can help bodybuilders and athletes achieve, as well as its short and longer-term negative impacts.

The ideal male dosage of YK-11 is between 2mg and 5mg daily. Women will be best served at a much lower dosage, sometimes as low as 0.5mg daily, giving excellent results. With time and evaluating results and side effects, some women will increase YK-11 to 2mg daily.

If you choose to give YK-11 a try, always buy from a reputable source because low quality and counterfeits do exist with this compound, and taking such products is not only detrimental to your results but, more importantly, is a huge health risk.

Increased aggression is a problem that some experience with YK-11, and again, this is going to be dosage-dependent as well as highly individual. If you are normally prone to anger or have a short fuse, then YK-11 is likely to trigger that, and this needs to be kept in mind when formulating your dosage.

We do see some unique side effects with this SARM that aren’t often seen with other compounds, and some of these are similar to what anabolic steroids can produce in addition to increased aggression. This can include unexpected hair growth plus joint weakening, as well as the aforementioned liver toxicity risk. This makes YK-11 one of the more potent SARMs in terms of its positive effects and negatives.

The big question with YK-11 is: Do the benefits outweigh the risks? This isn’t something we are so concerned about with most other SARMs because none are as closely related to steroids as this one is. And it’s a question that ultimately only YOU can answer. If you’re used to using or just learning about SARMs, you need to change your mindset when it comes to YK-11 and think of it as a steroid.

And I’m with many other guys on this one: YK-11 is best used as an injectable. If you don’t want to inject? You can still get some benefits with it orally, but there are better options in the world of SARMs if you want to stick with orals.

— Furious Joe