Source comparison
How Peptides for Growth Hormone Deficiency Work: Protocol vs Mechanism Comparison
GHRH Analogues (CJC-1295, Sermorelin) Binds GHRH receptors on pituitary somatotrophs, triggering cAMP-mediated GH release Once daily (CJC-1295 has 6–8 day half-life; Sermorelin requires twice-daily dosing) 100–300 mcg per injection Requires GHRP co-administrat
This comparison does not assign a generated winner or score.
- GHRH Analogues (CJC-1295, Sermorelin)
- Binds GHRH receptors on pituitary somatotrophs, triggering cAMP-mediated GH release
- Once daily (CJC-1295 has 6–8 day half-life; Sermorelin requires twice-daily dosing)
- 100–300 mcg per injection
- Requires GHRP co-administration for full effect; GHRH alone produces modest GH pulse
- CJC-1295 is preferred for convenience. Longer half-life means fewer injections and more stable IGF-1 elevation
- GHRPs (GHRP-2, GHRP-6, Ipamorelin)
- Mimics ghrelin, binds growth hormone secretagogue receptors (GHS-R1a), amplifies GH pulse and inhibits somatostatin
- 1–3 times daily
- Works synergistically with GHRH analogues; solo use produces smaller GH elevation
- GHRP-2 produces strongest GH response but increases cortisol and prolactin slightly; Ipamorelin is cleanest (no cortisol spike) but weaker GH pulse
- Oral Ghrelin Mimetics (MK-677 / Ibutamoren)
- Oral GHS-R1a agonist; sustained ghrelin receptor activation over 24 hours
- Once daily (typically before bed)
- 12.5–25 mg per day
- Can replace injectable GHRPs but desensitises receptors with continuous use; no GHRH synergy
- MK-677 simplifies protocol (no injections) but long-term use (beyond 6 months) shows diminishing IGF-1 response. Best for short cycles
- IGF-1 LR3 (Direct IGF-1 Analogue)
- Bypasses GH entirely; directly activates IGF-1 receptors in muscle and liver
- 3–5 times per week
- 40–80 mcg per injection
- No synergy. Works independently of pituitary function
- Used when pituitary reserve is completely absent; higher risk of hypoglycemia and requires glucose monitoring