What it is
GHRP-2 is a 6-amino-acid GHRP that stimulates GH release via the ghrelin receptor. Older than ipamorelin but with broader activity including some cortisol and appetite stimulation. GHRP-2 binds the ghrelin receptor (GHS-R1a) on pituitary somatotrophs, triggering GH release. Unlike ipamorelin, GHRP-2 also produces measurable cortisol and prolactin elevation and stimulates appetite via the ghrelin pathway. GHRP-2 is one of the original GHRPs. Compared to ipamorelin it produces stronger GH pulses but with measurable cortisol and prolactin elevation, plus marked appetite stimulation via ghrelin pathway activation. The appetite effect makes it suitable for protocols where increased intake is desirable (e.g., bulking, post-illness weight gain).
Evidence boundary
Investigational. The schedule comes from research notes, not validated human evidence, and should not be treated as a clinical standard.
Preparation and measurement
Reconstitution: 5 mg vial + 3 mL BAC = 1.67 mg/mL.
Concentration matches.
Reference schedule
| Phase | Dose | Draw / measure | Frequency | Weekly total |
|---|---|---|---|---|
| Weeks 1–2 (titration) | 100 mcg | 6 U (0.06 mL) | 1–3× daily | 700 mcg/week |
| Weeks 3–4 | 150 mcg | 9 U (0.09 mL) | 1–3× daily | 1.05 mg/week |
| Weeks 5–8 | 200 mcg | 12 U (0.12 mL) | 1–3× daily | 1.4 mg/week |
| Weeks 9–12 (optional) | 275 mcg | 16.5 U (0.165 mL) | 1–3× daily | 1.925 mg/week |
Weeks 1–2 (titration)
- Dose
- 100 mcg
- Draw / measure
- 6 U (0.06 mL)
- Frequency
- 1–3× daily
- Weekly total
- 700 mcg/week
Weeks 3–4
- Dose
- 150 mcg
- Draw / measure
- 9 U (0.09 mL)
- Frequency
- 1–3× daily
- Weekly total
- 1.05 mg/week
Weeks 5–8
- Dose
- 200 mcg
- Draw / measure
- 12 U (0.12 mL)
- Frequency
- 1–3× daily
- Weekly total
- 1.4 mg/week
Weeks 9–12 (optional)
- Dose
- 275 mcg
- Draw / measure
- 16.5 U (0.165 mL)
- Frequency
- 1–3× daily
- Weekly total
- 1.925 mg/week
Weekly totals apply only during the active phase.
Titration rules
- Standard (200 mcg, 2–3× daily): Common research protocol.
- Timing: Avoid eating for 30+ minutes post-dose. Pre-meal dosing leverages the appetite-stimulation for protocols where weight gain is desirable.
Cycle length and breaks
What to monitor
- Strong GH pulse via ghrelin receptor.
- Useful in protocols where appetite stimulation is desired.
- Synergistic with GHRH analogs.
- Cortisol and prolactin elevation.
- Significant appetite increase.
- Injection-site reactions.
- Mild fluid retention.
Practical rules
- Manage appetite stimulation with planned meals.
- Avoid eating for 30+ min post-dose.
- Resistance training to leverage GH pulse.
- Subcutaneous into abdomen, thigh, or upper arm.
- Rotate sites with each dose.