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YK-11 stimulates muscle cells to produce more follistatin, a strong inhibitor of myostatin.

Qty: 30 tablets


Supplied for Research Purposes Only

This information and product is provided for research purposes only. We do not provide any advice on the usage of these products as UK Law prevents this. Customers should check the legality of this product in their own country prior to purchase.

Benefits and uses:

Increased muscle growth

Strengthened bones

Increased strength


25mg once per day

What is YK11?

YK-11 is a steroidal SARM (Selective Androgen Receptor Modulator). It is a Myostatin inhibitor particularly. It is regarded as one of the strongest SARMs on the market, and its potency is comparable to that of some steroids.

Is it actually a SARM?

SARMs, such as LGD-4033 and Ostarine (MK2866), are gaining popularity since they have little adverse effects and excellent outcomes. However, since everyone is constantly seeking the next great thing, or in this case, the next major SARM, YK-11 has become highly popular. The issue is that YK-11 is not a SARM; rather, it is an untested steroid that has not been tried on humans or animals.

In their 2011 research, Kanno Y et al. proposed that YK-11, also known as 1-Methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic Acid Methyl Ester, is a partial agonist of the androgen receptor and MIGHT function as a selective androgen receptor modulator. They then published a second report in 2013 referring to YK11 as a selective androgen receptor modulator. Although the data presented in these papers appears to have no scientific flaws, it is wrong to refer to YK11 as a SARM rather than a steroid.

Because it uses a steroid nomenclature, YK-11 is not a SARM. A system of names or terms, or the guidelines for creating these terms in a certain sector of the arts or sciences, is known as nomenclature. While there is currently no agreed global nomenclature for SARMs, there is one for steroids, which YK-11 fully fits within, demonstrating that it is in fact a synthetic steroid.

The backbone of all steroids is the same, as seen on your top left. The structures of testosterone and trenbolone are shown here, and you can see that they are very similar.

YK-11 is not a SARM because it shares the same steroid molecular structure as all other steroids.

Now that it's a steroid, some folks may be thinking, "Great, better results!"

The issue is that YK-11 has never been tested and no authorised researchers, pharmaceutical companies, or SARMs companies have kept up their research on it. Rats or mice have not been used in any YK studies, and there have been no animal tests either. Only C2C12 cells from a differentiable myoblast cell line in mice are the subject of YK's in vitro research. In other words, simply a test tube has been used for testing. It is clear from this experiment that at specific concentrations, it can lead to muscle differentiation. But as there is ZERO information on its metabolism, this cannot be directly converted into human dosages. However, given that it is a synthetic steroid, one could counter that making an educated prediction based on the metabolism of other synthetic steroids would provide a general idea of its metabolism. However, there was nothing real or unquestionably no proof.

Is PCT necessary?

Given that YK-11 is a steroid, a robust PCT will very certainly be required after treatment.

Due to the 4 methylation groups in its name, YK-11 is probably hepatotoxic to the liver. Having said that, their location makes it unlikely that they will be seriously harmful to the liver. Liver readings are probably going to go up, but not dramatically.

The half-life of YK-11 has not been established, and neither have any possible negative effects.

What makes YK-11 so puwerful?

It was hypothesised in the 2011 paper that YK will function as an anti-androgen (stopping testosterone etc binding in the body). Having some anabolic potential at low Test/DHT concentrations. It is believed that little muscle mass gains can be obtained directly from it because it is a product of DHT. However, it's possible that muscle retention, hardness, strength, and libido will all rise. Although it is frequently promoted as a mass builder, it would be a compound bodybuilders would run prior to a show rather than in the offseason.

According to the 2011 paper, YK was chemically created from ethisterone (a steroidal progestin), and because of its resemblance to Norethynodrel in structure, it is expected to either stimulate or inhibit progesterone receptors. However, because it hasn't been demonstrated, this is primarily based on scientific theory rather than studies.

Myostatin Inhibitor YK11

99 percent of products that make this claim are ineffective or completely ineffective in inhibiting myostatin. YK has a greater ability than DHT or other synthetic steroids to raise follistatin levels. which might mitigate the negative effects indicated above. However, we have no idea how much or how effective it actually is because there is again ZERO evidence to support it.

What YK dose is right for you?

No proper dosage exists for YK. Companies frequently use 5mg per capsule, however it is impossible to know whether this is considerably too much or way too little.


 Kanno Y, Hikosaka R, Zhang SY, Inoue Y, Nakahama T, Kato K, Yamaguchi A, Tominaga N, Kohra S, Arizono K, Inouye Y (2011). "(17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester (YK11) is a partial agonist of the androgen receptor". Biological & Pharmaceutical Bulletin. 34 (3): 318–23. doi:10.1248/bpb.34.318. PMID 21372378.

 Kanno Y, Ota R, Someya K, Kusakabe T, Kato K, Inouye Y (2013). "Selective androgen receptor modulator, YK11, regulates myogenic differentiation of C2C12 myoblasts by follistatin expression". Biological & Pharmaceutical Bulletin. 36 (9): 1460–5. doi:10.1248/bpb.b13-00231. PMID 23995658.

 Lee, Su Jin; Gharbi, Amal; Shin, Joo Eun; Jung, In Duk; Park, Yeong Min (2021-03-05). "Myostatin inhibitor YK11 as a preventative health supplement for bacterial sepsis". Biochemical and Biophysical Research Communications. 543: 1–7. doi:10.1016/j.bbrc.2021.01.030. ISSN 1090-2104. PMID 33588136.


Androgen receptor modulators

This stuf is too strong man. Can't stop eatin

Mosi A

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