YK-11 and RAD-140 Stack
YK-11 and RAD-140 Stack. When it comes to building lean muscle mass with precision and speed, SARMs (Selective Androgen Receptor Modulators) like YK-11 and RAD-140 have carved out a dominant place in the performance enhancement world. But stacking these two together? That’s where the magic happens — and the muscle really starts to show.
YK-11, a unique myostatin inhibitor, and RAD-140, one of the most anabolic SARMs available, form a synergy that maximizes muscle growth without the bloating or water retention typically seen with traditional steroids. This stack is designed for athletes and bodybuilders looking to gain size, increase strength, and stay shredded — all at once.
Whether you’re deep into your hypertrophy phase or looking for an edge during a recomp protocol, this article breaks down how the YK-11 and RAD-140 stack works, what the research says, and how to structure your cycle for results — with fewer side effects.
If you’re serious about pushing your physique forward, read on.
Need a supplement stack to match your goals? Check out the Swolverine Muscle Growth Stack to support your cycle with clinically dosed, performance-backed ingredients.
What Is YK-11?
YK-11 is one of the most unique compounds in the world of SARMs — although technically, it isn’t a true SARM. It’s often classified as a myostatin inhibitor with partial SARM activity, meaning it not only stimulates muscle growth by binding to androgen receptors but also limits the body’s natural ability to suppress growth through myostatin.
Myostatin is a protein that regulates muscle cell growth — in essence, it tells your body when to stop building muscle. YK-11 works by increasing follistatin, a natural antagonist to myostatin, allowing muscle cells to continue growing beyond what your body would normally permit.
This mechanism makes YK-11 incredibly powerful for:
→ Increasing muscle fiber size and density
→ Improving muscle differentiation at the cellular level
→ Gaining lean mass without significant water retention
→ Producing a hard, dry look when paired with a clean diet
What Is RAD-140 (Testolone)?
RAD-140, also known as Testolone, is widely considered one of the most potent SARMs on the market. It was originally developed as a safer alternative to testosterone replacement therapy — designed to mimic the anabolic effects of testosterone without the unwanted side effects like prostate enlargement, testicular shrinkage, or estrogen conversion.
Here’s what RAD-140 brings to the table:
→ Rapid lean muscle growth without water retention
→ Improved strength, power output, and endurance
→ Increased vascularity and hardness during a recomp or cutting phase
→ Minimal aromatization (estrogen conversion), making it ideal for dry gains
Benefits of YK-11 and RAD-140 Stack
Stacking YK-11 with RAD-140 offers one of the most aggressive lean mass protocols among all selective androgen receptor modulators. While either compound is effective alone, their combination leads to exponential results — particularly when muscle growth, strength, and aesthetics are the goal.
benefits:
→ Accelerated Lean Muscle Growth
YK-11 removes the myostatin limitation, allowing muscle fibers to grow beyond their natural capacity. RAD-140 then activates the androgen receptors to maximize protein synthesis, giving you faster, more visible muscle gains.
→ Dry, Dense, and Hard Physique
Unlike bulking stacks that leave you bloated, this combination produces hard, grainy muscle with minimal water retention — especially when paired with a clean diet and effective hydration support like INTRA EAA.
→ Increased Strength and Explosiveness
RAD-140 is known for rapid strength gains. Users often report faster PRs, improved bar speed, and higher endurance under load — while YK-11 improves contractile muscle quality, making each rep more efficient.
→ Enhanced Vascularity and Muscle Fullness
With increased lean tissue and reduced subcutaneous fluid, you’ll notice improved vascularity and muscle separation. Supporting this with Clean Carbs can help maintain glycogen stores for that full, pumped look.
→ Minimal Estrogenic Side Effects
Neither compound converts to estrogen (aromatize), reducing the risk of gynecomastia, mood swings, and unwanted water weight — making this stack ideal for those who want size without puffiness.
→ Fat Loss Support via Recomp
Increased lean muscle mass naturally elevates metabolic rate. Combined with the performance benefits, this stack can help preserve or even reduce body fat levels when paired with Citrulline Malate and cardio-focused training blocks.
Recommended Dosage and Cycle Guidelines
To maximize results and minimize side effects, it’s essential to approach the YK-11 and RAD-140 stack with a strategic dosing protocol. Both compounds are powerful on their own, and together, they demand discipline, proper timing, and support supplementation.
Here’s a typical guideline for experienced users:
➤ YK-11 Dosage
- Beginner dose: 5 mg per day
- Advanced dose: Up to 10 mg per day
- Split dosing (morning + evening) is recommended due to its short half-life (~6–10 hours)
YK-11 is methylated, meaning it’s liver-active. On-cycle liver support with Liver Cleanse is highly recommended.
➤ RAD-140 Dosage
- Beginner dose: 10 mg per day
- Advanced dose: 15–20 mg per day
- Once-daily dosing is sufficient due to its longer half-life (~16–20 hours)
RAD-140 is generally well-tolerated, but suppression can still occur, especially at higher doses.