MK-677, RAD-140, or Andarine S4: Which Is Best for Bulking and Strength?
Chasing massive muscle gains and strength? MK-677 (Ibutamoren), RAD-140 (Testolone), and Andarine (S4) are top compounds in bodybuilding research for bulking. Each delivers unique benefits for size and power, but which is best? This comparison breaks down their mechanisms, muscle-building potential, strength gains, and PCT requirements to help you decide.
What Are MK-677, RAD-140, and Andarine S4?
- MK-677 (Ibutamoren): A growth hormone secretagogue boosting GH and IGF-1. Dose: 10-20 mg daily, 8-16 weeks.
- RAD-140 (Testolone): A SARM targeting muscle and bone for anabolic growth. Dose: 10 mg daily, 8-12 weeks.
- Andarine (S4): A SARM enhancing lean muscle and strength. Dose: 25-50 mg daily (split doses), 8-12 weeks.
Origins of the Compounds
- MK-677: Developed by Merck in the ‘90s for growth hormone deficiencies, it’s valued for recovery and mass without testosterone suppression.
- RAD-140: Created by Radius Health in the 2000s for muscle-wasting conditions, it’s a bulking powerhouse but requires PCT.
- Andarine S4: Developed by GTx for muscle wasting, it’s known for lean gains and may need PCT at higher doses.
Comparing MK-677, RAD-140, and Andarine S4 for Bulking and Strength
MK-677: Growth Hormone Amplifier
- Mechanism: Mimics ghrelin, boosting GH and IGF-1 by up to 50% in trials, driving protein synthesis and recovery. Studies show 1-2 kg lean mass gains in 16 weeks without training, 2-3 kg with training in 8-12 weeks.
- Bulking: Supports steady mass gains via enhanced appetite and recovery. Best for long-term bulking with minimal side effects.
- Strength: Moderate strength gains (10-15% lift increases) tied to recovery and muscle retention.
- PCT: Not required—non-suppressive to testosterone.
- Pros: No PCT, boosts sleep, aids fat loss (5-7% body fat reduction).
- Cons: Water retention, hunger spikes, mild insulin sensitivity changes.
- Best For: Beginners or long-term bulking with recovery focus.
RAD-140: Anabolic Beast
- Mechanism: Binds androgen receptors (Ki ~7 nM), activating mTOR and MAPK for protein synthesis. Trials show 3-4 kg lean mass gains in 4-8 weeks, with 20-30% strength boosts.
- Bulking: Excels for rapid, high-volume muscle gains, ideal for aggressive bulking cycles.
- Strength: Significant strength increases, perfect for power-focused training.
- PCT: Required due to testosterone suppression. Use Recharge 2.0 post-cycle.
- Pros: Fastest muscle and strength gains, potent anabolic effects.
- Cons: Suppression, potential fatigue, requires PCT.
- Best For: Experienced users aiming for quick, maxed-out bulking.
Andarine S4: Lean Muscle Builder
- Mechanism: Binds androgen receptors (Ki ~4 nM), promoting protein synthesis for lean muscle. Studies suggest 1-2 kg lean mass gains in 8 weeks, with fat loss and definition.
- Bulking: Better for lean bulking or recomp, adding quality muscle without bloat.
- Strength: Moderate strength gains (10-20% lift increases), good for lean power.
- PCT: May be needed at higher doses (50 mg+) due to mild suppression; lower doses (25 mg) often skip PCT.
- Pros: Lean gains, fat loss, defined look, minimal water retention.
- Cons: Possible vision side effects (yellow tint) at high doses, milder gains.
- Best For: Users wanting lean, defined muscle with less suppression risk.
Which Is Best for Bulking and Strength?
- Best for Bulking: RAD-140 leads for sheer size, delivering 3-4 kg lean mass in 4-8 weeks, outpacing MK-677’s slower 2-3 kg and Andarine’s 1-2 kg. Its anabolic potency is unmatched for aggressive bulking.
- Best for Strength: RAD-140 again shines with 20-30% lift increases, followed by Andarine (10-20%) and MK-677 (10-15%). RAD-140’s strength gains are ideal for power-focused goals.
- Best for Beginners/Safety: MK-677 wins for its non-suppressive nature, no PCT requirement, and milder side effects, making it safer for new users or longer cycles.
- Best for Lean Bulking: Andarine S4 excels for quality, lean muscle with fat loss, ideal for those prioritizing definition alongside size.
Why Stack MK-677, RAD-140, and Andarine S4?
Stacking MK-677, RAD-140, and Andarine S4 creates a synergistic MK-677 RAD-140 Andarine bulking powerhouse:
- Massive Gains: RAD-140’s anabolic drive, MK-677’s GH boost, and Andarine’s lean mass focus yield 4-6 kg in 8-12 weeks.
- Strength Surge: RAD-140 and Andarine ramp up power; MK-677 aids recovery for intense sessions.
- Lean Definition: Andarine and MK-677 trim fat, enhancing muscle visibility.
- Recovery: MK-677’s sleep and repair benefits support RAD-140 and Andarine’s growth.
Bloodwork Monitoring
Bloodwork is vital, especially for RAD-140 and Andarine’s potential suppression. Test:
- Total/Free Testosterone: Monitor suppression (RAD-140, high-dose Andarine).
- Liver Enzymes (ALT, AST): Check for strain.
- Lipid Panel: Track cholesterol.
- IGF-1: Assess MK-677 effects.
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Maximising the Stack
- Nutrition: High-protein (1.6-2.2 g/kg body weight), moderate carbs for energy.
- Training: Heavy lifts for RAD-140; volume for Andarine; recovery-focused for MK-677.
- Timing: MK-677 at night (hunger/sleep); RAD-140 morning; Andarine split doses.
- Cycle: 8-12 weeks, with PCT for RAD-140/Andarine.
Considerations
Limited human data exists; preclinical studies dominate. Side effects include RAD-140 suppression, Andarine vision issues, and MK-677 water retention. Bloodwork and professional guidance are crucial.
Protocol
- MK-677: 1-2 capsules (10-20 mg) daily, evening.
- RAD-140: 1-2 capsules (10 mg) daily, morning.
- Andarine S4: 1-2 tablets (25-50 mg) daily, split doses.
- Cycle: 8-12 weeks.
- PCT: Required for RAD-140, possibly Andarine; use Recharge 2.0.
Ready to Pack on Serious Size?
Wanna pile on muscle and boost strength? Smash your goals with MK-677, RAD-140, or Andarine S4
Disclaimer: The products discussed are for research purposes only and not for human consumption. Do your research and consult a professional before use. APH Science is not responsible for misuse.
