YK-11
A profile on YK-11, a unique hybrid compound that acts as both a SARM and a Myostatin Inhibitor, derived from 19-Nortestosterone.
YK-11
YK-11 is often categorized as a SARM, but chemically it is a synthetic steroid. It is a gene-selective partial agonist of the androgen receptor.
It is unique because it is the only SARM that possesses a steroidal backbone (derived from 19-Nortestosterone, like Deca or Tren). Furthermore, it works by inhibiting Myostatin, a protein that naturally limits muscle growth.
Quick Specs
| Property | Value |
|---|---|
| Active Compound | YK-11 |
| Half-Life | ~6-10 Hours |
| Detection Time | Unknown |
| Anabolic/Androgenic Ratio | Not standardized |
| Chemical Family | Steroidal SARM (19-Nor Derivative) |
| Administration | Oral / Injectable |
Mechanism of Action
- SARM Action: It acts as a partial agonist at the androgen receptor.
- Myostatin Inhibition: YK-11 induces muscle cells to produce more Follistatin. Follistatin is a potent inhibitor of Myostatin. By lowering Myostatin, the "ceiling" on muscle growth is raised, allowing for rapid hypertrophy beyond natural limits.
Pharmacokinetics & Dosing
Half-Life: ~6-10 Hours
- Frequency: Twice Daily (AM/PM) is recommended.
- Dosage:
- Beginner: 5mg/day.
- Advanced: 10mg - 15mg/day.
- Note: Above 15mg, joint pain tends to become severe.
Primary Effects
1. Rapid Hypertrophy
YK-11 creates a very dry, full look. It adds size quickly, similar to oral steroids like Turinabol.
2. Strength
Significant strength increases are reported within week 2.
3. Hardness
Does not aromatize, leading to zero water retention.
Side Effects & Harm Reduction
Joint Health:
Dry Tendons: A very common side effect of YK-11 is joint and tendon pain. It is believed that the rapid increase in strength outpaces tendon adaptation, or that the inhibition of myostatin affects tendon integrity. Injury risk increases on YK-11.
1. Suppression
Because it has a steroidal backbone, it is more suppressive than Ostarine or LGD. A PCT is mandatory.
2. Liver Toxicity
It is methylated. Liver support (NAC) is required.
3. Hair Loss
Aggressive hair shedding is common due to its DHT-like properties.
Tracking YK-11
Using the Anabolic Tracker app:
- Inventory: Add YK-11.
- Scheduling: Twice Daily.
- Metrics: Track Joint Pain (1-10) and Strength.
- Notes: Be hyper-aware of tendon stiffness. If joints hurt, lower the weight or stop the cycle.
Disclaimer:
This guide is for informational purposes only. YK-11 is a research chemical not approved for human use.