Source comparison
Sermorelin vs Ipamorelin vs Combined Protocol — Research Outcomes
Sermorelin alone (300 mcg) 6.2 ng/mL 90–120 minutes Direct GHRH receptor activation on somatotrophs Low. Pulsatile dosing preserves receptor sensitivity Effective for initiating GH release but limited by endogenous somatostatin tone, which caps pulse amplitude
This comparison does not assign a generated winner or score.
- Sermorelin alone (300 mcg)
- 6.2 ng/mL
- 90–120 minutes
- Direct GHRH receptor activation on somatotrophs
- Low. Pulsatile dosing preserves receptor sensitivity
- Effective for initiating GH release but limited by endogenous somatostatin tone, which caps pulse amplitude at 40–50% of theoretical maximum
- Ipamorelin alone (300 mcg)
- 4.8 ng/mL
- 2–3 hours
- Ghrelin receptor agonism + partial somatostatin suppression
- Minimal. Highly selective for GHS-R1a without cortisol or prolactin elevation
- Lower peak amplitude than sermorelin but longer duration of action; most useful when extended GH elevation is preferred over peak intensity
- Sermorelin + Ipamorelin (300 mcg each)
- 18.3 ng/mL
- 2.5–3.5 hours
- Dual-pathway activation: GHRH stimulation + somatostatin blockade
- Low when dosed 5–7 days/week with 2-day breaks
- Produces the highest peak GH levels and longest duration of supraphysiological GH. The standard for research protocols prioritizing anabolic signaling and lipolysis
- CJC-1295 + Ipamorelin (alternative)
- 14–16 ng/mL
- 6–8 days (CJC half-life)
- Long-acting GHRH analog + ghrelin agonism
- Moderate. Prolonged GHRH stimulation may reduce pituitary responsiveness over time
- Higher baseline GH elevation but blunted peak amplitude; less ideal for preserving natural pulsatility compared to sermorelin protocols
- The comparison makes clear why sermorelin-ipamorelin remains the preferred combination in most research settings: it produces the highest acute GH pulse while preserving the pulsatile secretion pattern that prevents receptor desensitization. CJC-1295 Ipamorelin combinations offer convenience (fewer injections due to CJC's extended half-life), but at the cost of flattened GH curves that more closely resemble exogenous GH administration than natural secretion.