Ipamorelin is a synthetic pentapeptide categorized as a growth hormone releasing peptide (GHRP) and studied as a ghrelin receptor (GHS-R1a) agonist. It is often discussed as a more selective GH secretagogue compared with older GHRPs, with less reported stimulation of cortisol and prolactin in some studies.
— 5 mg Vial —
Reconstitute: Add 3.0 mL bacteriostatic water → ~1.67 mg/mL concentration.
Typical daily range: 100–250 mcg once daily (gradual titration recommended).
Easy measuring: At 1.67 mg/mL, 1 unit = 0.01 mL ≈ 16.7 mcg on a U-100 insulin syringe.
Storage: Lyophilized: 2–8 °C or freeze at −20 °C; reconstituted: refrigerate at 2–8 °C, use within ~4 weeks.
Schedule: Daily subcutaneous injections for 8–12 weeks (extend to 16 weeks if desired), followed by a 2–4 week pause.
Cycle Length: 8–12 weeks; optional extension to 16 weeks, followed by 2–4 week off-cycle.
Goal: Stimulate endogenous growth hormone release to support muscle growth, fat metabolism, and tissue repair.
Frequency: Inject once daily subcutaneously, ideally 30–60 minutes before bedtime on an empty stomach to synergize with natural nocturnal GH secretion.
| Phase | Dose | Syringe (U-100) |
|---|---|---|
| Weeks 1–2 | 100 mcg | 6 units (0.06 mL) |
| Weeks 3–4 | 150 mcg | 9 units (0.09 mL) |
| Weeks 5–8 | 200 mcg | 12 units (0.12 mL) |
| Weeks 9–12 | 250 mcg | 15 units (0.15 mL) |
— 10 mg Vial —
Reconstitute: Add 3.0 mL bacteriostatic water → ~3.33 mg/mL concentration.
Typical daily range: 100–300 mcg once daily (gradual titration recommended).
Easy measuring: At 3.33 mg/mL, 1 unit = 0.01 mL ≈ 33 mcg on a U-100 insulin syringe.
Storage: Lyophilized: 2–8 °C or freeze at −20 °C; reconstituted: refrigerate at 2–8 °C, use within ~4 weeks.
Schedule: Daily subcutaneous injections for 8–12 weeks, followed by a 2–4 week pause.
Cycle Length: 8–12 weeks; optional extension to 16 weeks, followed by 2–4 week off-cycle.
Goal: Stimulate endogenous growth hormone release to support muscle growth, fat metabolism, and tissue repair.
Frequency: Inject once daily subcutaneously, ideally 30–60 minutes before bedtime on an empty stomach to synergize with natural nocturnal GH secretion.
| Phase | Dose | Syringe (U-100) |
|---|---|---|
| Weeks 1–2 | 100 mcg | 3 units (0.03 mL) |
| Weeks 3–4 | 150 mcg | 5 units (0.05 mL) |
| Weeks 5–8 | 200 mcg | 6 units (0.06 mL) |
| Weeks 9–12 | 250 mcg | 8 units (0.08 mL) |
Ipamorelin was developed as a GH secretagogue with relatively strong GH release and comparatively limited effects on ACTH/cortisol pathways versus some earlier GHRPs. In research circles it is frequently paired with GHRH analogs (e.g., Mod GRF 1-29 / CJC no DAC) to amplify pulsatile GH release.
- Increased GH pulse amplitude (acute stimulation in studies).
- Sleep/recovery narratives (largely anecdotal in non-clinical settings).
- Body composition hypotheses via GH/IGF-1 axis (depends on dose/duration; human outcomes limited).
- Support of GHRH synergy when co-administered with GHRH analogs (mechanistic rationale).
Ipamorelin acts primarily as an agonist at the growth hormone secretagogue receptor (GHS-R1a), a receptor also activated by endogenous ghrelin. Activation influences hypothalamic and pituitary signaling to increase pulsatile GH secretion. In combination with a GHRH analog, the pathway can be synergistic: GHRH provides stimulatory drive while GHRP/GHS-R signaling can reduce somatostatin tone and enhance GH pulses (context-dependent).
- Injection site irritation (if injected).
- Water retention, tingling, appetite changes (possible GH/ghrelin-pathway effects).
- Headache, fatigue (anecdotal).
- Elevated fasting glucose/insulin resistance risk with prolonged GH-axis manipulation (theoretical/depends on context).
- Pregnancy/breastfeeding (insufficient safety data).
- Active malignancy or history of cancer (GH/IGF-1 axis is a theoretical concern).
- Uncontrolled diabetes (GH-axis modulation may affect glucose handling).
In research practice, ipamorelin is commonly administered SubQ due to convenience and low injection volume. Some choose IM, but there is limited evidence that IM provides meaningfully different pharmacodynamics for small peptides at typical microgram doses.
- CJC no DAC (Mod GRF 1-29): commonly paired to support GH pulsatility (mechanistic synergy).
- Sleep hygiene + training periodization: often emphasized alongside GH-axis peptide discussions.
- Avoid stacking multiple GHRPs without a clear rationale due to compounding unknowns.
- Ipamorelin stimulates GH release with limited ACTH/cortisol effects (early human pharmacology). J Clin Endocrinol Metab. 1997. PMID: 9024231
- Growth hormone secretagogue receptor biology (ghrelin receptor). Endocr Rev. 2004. PMID: 15294882
- Ghrelin and GHS-R physiology relevant to GH release and appetite. Physiol Rev. 2005. PMID: 15987801
- GHRP + GHRH synergy and somatostatin interactions (human endocrine studies). J Clin Endocrinol Metab. 1994. PMID: 8175955
- GH secretagogues overview and clinical pharmacology context. Trends Endocrinol Metab. 1999. PMID: 10407421
- GHS-R agonists and GH pulsatility concepts (review). Front Neuroendocrinol. 2008. PMID: 18406015