GHRP-1 for Muscle Gain
First-generation growth hormone-releasing hexapeptide; precursor to GHRP-2/-6.
Why GHRP-1 for muscle gain?
GHRP-1 is the original synthetic ghrelin-mimetic hexapeptide developed by Bowers et al. in the late 1970s. It was the template that gave rise to GHRP-2 and GHRP-6, and is rarely sold today because both successors are stronger and cleaner. Most modern research relies on GHRP-2 instead.
Muscle Gain context: Increasing lean mass via GH/IGF-1 axis, satellite-cell activity, or anabolic signaling. GHRP-1 fits this goal because its category (Performance) and benefit profile align with the underlying mechanism.
Benefits relevant to muscle gain
- Lean mass support
Reference dosing by bodyweight
Anchored to the most-cited research dose (200 mcg @ 75 kg). Reference only.
| Bodyweight band | Reference dose range |
|---|---|
| <60 kg / <132 lb | 125–169 mcg |
| 60–75 kg / 132–165 lb | 153–207 mcg |
| 75–90 kg / 165–198 lb | 187–253 mcg |
| 90–105 kg / 198–231 lb | 221–299 mcg |
| >105 kg / >231 lb | 255–345 mcg |
Side effects to weigh against muscle gain benefit
- Mild cortisol/prolactin rise
- Flushing
- Injection-site irritation
Also researched for
Educational use only
This calculator is provided for research and educational purposes. Outputs are derived from the values you enter. Always verify your math and consult a licensed physician before acting on any result.