Research Disclaimer: This article is for informational and educational purposes only. SARMs are sold strictly as research compounds and are not intended for human consumption.
Best SARMs for Muscle Growth: Ranked by Research Evidence
Not all SARMs are created equal when it comes to building lean mass. Some are designed for cutting, some for endurance, and some are specifically engineered to maximise muscle protein synthesis and hypertrophy. Here’s what the research actually shows about the best compounds for muscle growth.
1. RAD-140 (Testolone) — The Strongest Option
RAD-140 consistently tops the list for lean mass gains, and for good reason. Developed by Radius Health for muscle wasting and breast cancer, it has the highest anabolic-to-androgenic ratio of any SARM studied — approximately 90:1 compared to testosterone’s 1:1.
What the research shows:
- Significant lean mass increases in preclinical models at low doses
- Entered Phase I clinical trials (breast cancer) — well-tolerated
- Strong binding affinity for androgen receptors in muscle tissue
- Neuroprotective properties documented in research
Best for: Maximum lean mass gains, strength increases, body recomposition
Typical research dose: 10-20mg/day for 8-12 weeks
Suppression level: Moderate to high — PCT recommended
2. LGD-4033 (Ligandrol) — The Clinical Favourite
LGD-4033 has the most robust human clinical data for muscle growth of any SARM. Viking Therapeutics’ Phase II trial results were genuinely impressive.
What the research shows:
- Phase II clinical trial: subjects gained 1.21kg lean mass in just 21 days at 1mg/day
- Dose-dependent increases in lean body mass
- Increased muscle strength (stair climbing speed improved significantly)
- Effects maintained even after discontinuation in some subjects
Best for: Lean bulking, strength, clinical-grade evidence
Typical research dose: 5-10mg/day for 8-12 weeks
Suppression level: Moderate — PCT recommended
3. YK-11 (Myostine) — The Myostatin Inhibitor
YK-11 operates differently from traditional SARMs. It acts as both a partial androgen receptor agonist and a myostatin inhibitor. Myostatin is the protein that limits muscle growth — blocking it essentially removes your body’s natural ceiling on hypertrophy.
What the research shows:
- Increases follistatin expression (the natural myostatin antagonist)
- Promotes osteoblast activity for bone strength
- Steroidal structure but selective action
- Limited human clinical data — mostly cell-based studies
Best for: Breaking through plateaus, advanced researchers who’ve used other SARMs
Typical research dose: 5-10mg/day for 6-8 weeks
Suppression level: Moderate to high — PCT recommended
4. Ostarine MK-2866 — The Proven Starter
Ostarine isn’t the most powerful SARM for pure mass, but it has the most clinical evidence and the best safety profile. It’s the compound most researchers start with.
What the research shows:
- Phase II trial: elderly subjects gained significant lean mass at just 3mg/day
- Muscle preservation during caloric deficit (cancer cachexia studies)
- No serious adverse events at clinical doses
- Mild suppression that recovers quickly
Best for: First-time researchers, lean gains with minimal sides, muscle preservation during cutting
Typical research dose: 10-25mg/day for 8-12 weeks
Suppression level: Mild — PCT optional at lower doses
5. ACP-105 — The Underrated Alternative
ACP-105 is less well-known but shows promising anabolic activity with potentially fewer side effects than RAD-140 or LGD-4033. Developed by Acadia Pharmaceuticals, it offers a middle ground.
What the research shows:
- Anabolic effects comparable to testosterone in preclinical models
- Lower androgenic activity than other SARMs
- Potential cognitive benefits documented in animal studies
Best for: Moderate gains with a lighter side effect profile
Typical research dose: 10-15mg/day for 8-12 weeks
Suppression level: Mild to moderate
Stacking for Maximum Growth
Some researchers combine compounds for synergistic effects. Popular mass-focused stacks include:
- Beginner Stack: Ostarine + MK-677 — lean gains with GH support, minimal suppression
- Intermediate Stack: RAD-140 + MK-677 — strong mass gains with appetite and recovery support
- Advanced Stack: RAD-140 + LGD-4033 + MK-677 — maximum anabolic environment
- Bulk Mass Stack: Full mass protocol for experienced researchers
Important: Don’t stack until you know how individual compounds affect you. Start with a single compound for your first cycle. See our cycling guide for protocol details.
Supporting Muscle Growth
No compound will compensate for poor fundamentals. Maximise results by ensuring:
- Caloric surplus — you need to eat above maintenance to grow
- Adequate protein — 1.6-2.2g per kg bodyweight
- Progressive overload — consistently increase training stimulus
- Sleep — 7-9 hours for optimal recovery and hormone production
- Consistency — compounds amplify effort, they don’t replace it
Product Quality Matters
With nearly half of SARMs products online containing incorrect or missing compounds (JAMA, 2017), sourcing from an HPLC-tested supplier isn’t optional — it’s essential. Every batch at SarmsUK is independently verified for identity and purity.
