Myostan (YK-11)

Myostan, known as YK-11, is a synthetic compound that combines the qualities of SARMs (Selective Androgen Receptor Modulators) and myostatin inhibitors. This unique combination has made YK-11 a popular option in the world of performance-enhancing supplements, especially among bodybuilders who are interested in muscle growth without the severe side effects often linked to traditional anabolic steroids.

YK-11 was developed with the aim of stimulating muscle growth by targeting specific receptors in the body. However, the exact details of its discovery are not entirely clear. It’s believed that YK-11 emerged from research exploring new ways to build muscle through innovative anabolic therapies. Early studies have focused on understanding how it influences muscle growth, but the research has been limited, especially when it comes to testing on animals and, even more so, on humans. This means there is still a lot we don’t know about YK-11, and ongoing studies are looking into its full range of effects.

One thing that makes YK-11 stand out from other SARMs is its two-way action. It partially activates androgen receptors—similar to other SARMs—but also blocks myostatin, a protein that naturally limits muscle growth. Myostatin acts as a “brake” on muscle growth to keep muscles from getting too large. By reducing myostatin levels, YK-11 helps to “release the brake,” allowing for greater muscle development. This targeted action appeals to athletes and bodybuilders because it may encourage muscle growth with fewer side effects on other parts of the body.

YK-11 is not approved for medical use, so it’s currently only available for research purposes. Despite this, it has gained popularity among fitness enthusiasts based on user reports claiming it promotes lean muscle growth and strength gains. It’s important to note, though, that there is very limited clinical data on its safety and effects over time. Next we will tell you about the main effects of YK-11 and try to explain its mechanism of action.

Effects and Benefits

YK-11 offers more than just muscle growth; it brings a range of benefits that make it popular among athletes and fitness enthusiasts. Here’s a closer look at what it can do:

• Enhanced muscle growth: YK-11 helps build muscle by working in two ways: it activates androgen receptors and blocks myostatin, a protein that usually limits muscle growth. This combination allows for more intense muscle growth than you’d typically see with other SARMs, helping muscles grow bigger and faster.
• Increased muscle density and hardness: Many users say YK-11 gives their muscles a firmer, more sculpted look. This is likely because it encourages lean muscle gains, focusing on actual muscle tissue growth rather than water retention or fat buildup.
• Improved strength levels: YK-11 promotes the development of Type II muscle fibers, which are the fibers most associated with strength and explosive power. This makes it a solid choice for athletes who need strength boosts, especially in sports that require power and endurance.
• Potential for fat loss: While YK-11 isn’t directly a fat-burner, its muscle-building effects and the increase in metabolism that comes with it might help burn more calories, which could indirectly support fat loss over time.
• Minimal water retention: Unlike many steroids that cause bloating, YK-11 seems to give a leaner, drier look. It doesn’t cause extra water retention, which means muscles look more defined.

With these effects, YK-11 appeals to athletes and bodybuilders who want both strength and a lean, defined look. Its unique benefits put it in a different league compared to traditional steroids and even most other SARMs, offering something that feels closer to "quality" muscle growth without the drawbacks often associated with other compounds.

Mechanism of Action

YK-11’s mechanism of action is complex but can be broken down into two main effects: androgen receptor activation and myostatin inhibition. Together, these two pathways set YK-11 apart and explain why it has such a strong impact on muscle growth.

• Androgen Receptor Binding: YK-11 works similarly to other SARMs by binding to androgen receptors, which are proteins found in muscle and bone cells. When these receptors are activated, they signal the cells to start building muscle and strengthening bone. However, YK-11 doesn’t fully activate these receptors; instead, it acts as a "partial agonist." This means it triggers some anabolic (muscle-building) effects but doesn’t overstimulate the receptors, which can help reduce side effects typically seen with stronger anabolic compounds. So, while it still promotes muscle growth and bone density, it aims to keep some of the androgenic side effects (like hair loss or aggression) lower than what you might see with traditional steroids.
• Myostatin Inhibition through Follistatin Increase: What really makes YK-11 stand out is its effect on myostatin, a natural protein in the body that limits how much muscle you can build. Normally, myostatin keeps muscles from growing beyond a certain point. But YK-11 increases the levels of another protein called follistatin, which blocks myostatin’s activity. By raising follistatin levels, YK-11 essentially removes the "brake" that myostatin puts on muscle growth, allowing muscles to grow larger than they naturally would (https://doi.org/10.1016/j.molstruc.2022.134281).

This image above shows how blocking the myostatin/activin pathway leads to muscle growth. On the left, a normal mouse , while the mouse on the right has much larger muscles due to myostatin inhibition. The diagram explains how muscle growth happens in this process. Myostatin normally limits muscle growth, but when it's blocked, muscle fibers can grow larger. Growth can occur without the help of satellite cells, or through satellite cell fusion, which supports even more muscle growth. This illustrates the potential impact of blocking myostatin, which is similar to how YK-11 is thought to work by boosting follistatin levels to inhibit myostatin and promote muscle growth.

• Enhanced Muscle Growth Pathways: The inhibition of myostatin also supports the creation of more muscle cell nuclei. These nuclei are essential because they increase the cell's capacity for protein synthesis, which is how muscles repair and grow stronger after workouts. With more nuclei, muscle cells can sustain higher levels of growth even during intense training. This added capacity for growth is what allows users to achieve hypertrophy (muscle enlargement) beyond normal limits.

By combining these effects, YK-11 creates a unique, powerful anabolic impact that goes beyond what SARMs alone can achieve. It targets key growth pathways in muscle tissue, encouraging significant muscle development while aiming to limit unwanted side effects, making it a compound of interest for those looking to build muscle more effectively.

Uses and Applications

Muscle hypertrophy and mass gains

YK-11 is primarily used by bodybuilders during bulking cycles to rapidly increase muscle size. By promoting hypertrophic growth through myostatin inhibition, YK-11 enables users to reach muscle size and density levels not typically achievable without performance-enhancing compounds (https://doi.org/10.1016/j.bbrc.2021.01.030).

Strength and power enhancement

Powerlifters and strength-focused athletes may use YK-11 to enhance muscle strength by promoting Type II muscle fibers, which are importantl for explosive force. This benefit aligns well with strength-based training regimens.

Lean muscle retention during cutting

For bodybuilders in a cutting phase, YK-11 may help preserve lean muscle mass while reducing body fat. Its ability to promote a dry, defined look without water retention makes it valuable for achieving a leaner physique without losing strength or muscle fullness.

Potential rehabilitation applications (experimental)

In research settings, there is growing interest in YK-11's potential for muscle preservation in cases of muscle-wasting diseases, where it could theoretically help retain muscle mass and improve quality of life.

Dosages, Administration, and Precautions

Our YK-11 comes in 5 mg tablets with 50 tablets per bottle. Here’s how to use it safely and effectively:

Dosage

For beginners, start with 5 mg per day (one tablet) to see how your body responds. If you’re experienced and feel comfortable, you can go up to 10 mg per day, split into two doses (one in the morning and one in the evening). YK-11 has a half-life of about 6-10 hours, so splitting the daily dose helps keep it active in your system throughout the day. Some advanced users may go as high as 15-20 mg per day, but it’s best to be cautious with higher doses.

How to take YK-11

 Take YK-11 tablets daily for a 4-8 week cycle. Because YK-11 is strong, keeping the cycles shorter helps lower the chance of side effects. Many people like to combine YK-11 with other compounds for even better results. Here are some popular combinations:

• With RAD-140 (Testolone): This is a common mix for users who want extra strength and muscle mass. RAD-140 is known for its strong muscle-building effects, which pair well with YK-11’s ability to make muscles look harder and more defined.
• With LGD-4033 (Ligandrol): People often stack YK-11 with Ligandrol during bulking cycles. Ligandrol helps add size, while YK-11 focuses on muscle density and shape, making for a well-rounded cycle.
• With MK-677 (Ibutamoren): YK-11 is sometimes combined with MK-677 to support recovery and improve sleep quality. MK-677 can increase growth hormone levels, which can help muscles repair faster and grow better.

If you’re stacking YK-11 with any other compounds, be sure to monitor your body closely, as combining these can increase the need for post-cycle therapy (PCT) to help get your natural testosterone levels back on track after the cycle.

Safety tips

YK-11 is still under research and has not been thoroughly studied in humans, so listen to your body and watch for any changes and side effects. Here are some safety tips to keep in mind:

• Monitor hormone levels: YK-11 may suppress natural testosterone production, so it is really important to do regular hormone testing during and after use is. A proper PCT will help you restore hormone levels after the cycle.
• Liver health: YK-11 and other oral compounds can put extra stress on your liver, as the liver has to process these substances. Since all oral forms of these types of supplements tend to be more toxic than injectables, it’s especially important to monitor liver health. Getting liver function tests done before and after your cycle can help you catch any issues early and manage liver strain effectively. For extra liver support, you can add TUDCA – it’s a popular supplement that protects the liver.
• Avoid overuse: Stick to recommended cycles and avoid prolonged use beyond 8 weeks. Continuous use could increase the risk of long-term side effects due to its potent effects on muscle and hormone levels.
• Hydration and nutrition. Since YK-11 puts extra stress on your muscles, it’s important to stay well-hydrated and eat a protein-rich diet to help with muscle recovery and keep your body healthy during the cycle.

Side Effects

• Suppression of natural testosterone production
• Liver toxicity (potentially elevated liver enzymes with prolonged use)
• Joint pain
• Acne and oily skin
• Aggression and mood changes
• Hair loss (androgenic side effects)
• Potential cardiovascular strain (elevated cholesterol levels)

How to store YK-11

• Keep in a cool, dry place.
• Avoid direct sunlight.
• Store at room temperature.
• Keep out of reach of children.