Ipamorelin (sometimes listed as NNC 26‑0161) is a selective growth hormone secretagogue (GHS) that binds the ghrelin receptor (GHSR‑1a) to trigger pulsatile GH release with minimal impact on ACTH or cortisol in preclinical models. Below you’ll find a concise answer, a properties table, outcomes‑focused mechanisms, step‑by‑step research‑handling guidance, comparisons vs. similar agents, a checklist, and FAQs.
Fast Answer / Executive Summary
Ipamorelin is a pentapeptide ghrelin‑receptor agonist that selectively stimulates pulsatile growth hormone (GH) release without measurably raising ACTH/cortisol in animal models, and produces a short‑acting GH pulse in humans (peak approximately 40 minutes; peptide half-life approximately 2 hours). Mechanistically, it amplifies GH output via GHSR‑1a, complementing the GHRH pathway. Educational use only.
Ipamorelin Entity Properties (educational)
| Property | Detail |
|---|---|
| Aliases | Ipamorelin; NNC 26‑0161; UNII: Y9M3S784Z6 |
| Family | Ghrelin receptor (GHSR‑1a) agonist; growth hormone secretagogue (GHS) |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 (pentapeptide) |
| Molecular Weight | ~711.9 Da |
| CAS | 170851-70-4 |
| Typical Diluent | Bacteriostatic Water for Injection, USP |
| Example Concentration | 5 mg vial + 2.0 mL = 2.5 mg/mL (educational math example) |
| Storage | Lyophilized: under -20 C; Solutions: 2-8 C short-term; freeze aliquots for longer storage |
Core Concepts
Ipamorelin is a selective GHS that activates GHSR‑1a to induce GH release while sparing ACTH/cortisol axes in animal models. Only ipamorelin avoided ACTH/cortisol elevations even at very high doses compared to GHRP-6 and GHRP-2 in swine studies.
GH pulse profile: In healthy volunteers, short infusions produced a single GH episode peaking around 0.67 hours (~40 minutes) with a peptide terminal half-life near 2 hours.
GHSR-1a physiology: GHSR‑1a is a GPCR expressed in pituitary somatotrophs and hypothalamic circuits. Endogenous ghrelin boosts GH by synergizing with GHRH and counteracting somatostatin inhibitory tone.
Selectivity vs. older GHRPs: Classic GHRPs (GHRP-6, hexarelin) can raise ACTH, cortisol, and prolactin especially with IV or high-dose exposure. Ipamorelin showed minimal ACTH/cortisol effects at doses greater than 200x its GH ED50.
Research Handling (Educational)
Note: For research use only. Follow your institution SOPs, the product COA, and applicable regulations.
- Verify identity: Confirm peptide name, lot, mass, purity on the COA. Cross-check CAS 170851-70-4, UNII Y9M3S784Z6.
- Plan concentration math before opening the vial (e.g., 5 mg + 2.0 mL = 2.5 mg/mL).
- Choose diluent: Bacteriostatic Water for Injection, USP for multi-dose use. Validate per SOP.
- Reconstitute gently: Inject diluent along the glass wall; swirl, avoid foaming and vigorous shaking.
- Label: Compound, lot, concentration, diluent, date/time, storage conditions.
- Store: Lyophilized at under -20 C; solutions at 2-8 C short-term; freeze aliquots to minimize freeze-thaw cycles.
- Dispose responsibly per hazardous waste and biosafety procedures.
Comparison: Ipamorelin vs. Common GHS/GHRH Agents
| Feature | Ipamorelin | GHRP-6 / GHRP-2 | CJC-1295 (DAC) | MK-677 (Ibutamoren) |
|---|---|---|---|---|
| Class | GHS; GHSR-1a agonist | GHS; GHSR-1a agonists | GHRH analogue (long-acting) | Oral GHS mimetic |
| GH Profile | Short pulse-like burst; peak ~0.67 h | Pulsatile; broader endocrine signal | Sustained GH/IGF-1 elevation days-weeks | Elevated 24-h GH/IGF-1 over months |
| ACTH/Cortisol | Minimal in animal tests | Often increases ACTH/cortisol and prolactin | GH-centric via GHRH receptor | Cortisol rises modestly; appetite increases |
| Half-life | ~2 h (peptide) | Short | ~6-9 days (effective) | Oral daily; long pharmacodynamics |
FAQs
1) What is Ipamorelin? A selective growth hormone secretagogue that activates the ghrelin receptor (GHSR-1a) to produce a brief, physiologic-like GH pulse. It is a pentapeptide developed to maximize GH selectivity relative to older GHRPs. Educational use only.
2) How long does Ipamorelin last? GH effect peaks at ~0.67 hours (~40 minutes) with a peptide half-life of ~2 hours based on infusion PK/PD modeling. The GH rise is episodic and returns to baseline.
3) Does Ipamorelin affect cortisol or prolactin like GHRP-6? Ipamorelin did not increase ACTH/cortisol above GHRH-like levels in animal studies even at greater than 200x its GH ED50, whereas GHRP-6 and related agents can raise ACTH/cortisol and prolactin.
4) Can Ipamorelin be combined with CJC-1295 in research? Ghrelin-pathway agonism (GHSR-1a) and GHRH signaling are mechanistically complementary. Research designs must weigh pulse timing vs. sustained exposure.
5) Is Ipamorelin permitted in sport? No. Growth-hormone-releasing factors and secretagogues including ipamorelin are on the WADA Prohibited List at all times.
6) What risks should researchers monitor with GH modulation? GH pathway modulation can relate to fluid retention, paresthesias, arthralgia, insulin sensitivity shifts, and lipid changes particularly when exposure is sustained.
Next Steps
- Ipamorelin 5 mg vial dosage protocol (educational): https://pep-dose.com/single-peptide-dosages/ipamorelin-5mg-vial-dosage-protocol/
- Ipamorelin 10 mg vial dosage protocol (educational): https://pep-dose.com/single-peptide-dosages/ipamorelin-10mg-vial-dosage-protocol/
- Buy Ipamorelin 5 mg (research use only): https://whitemarketpeptides.com/shop/xxxxx
- Buy Ipamorelin 10 mg (research use only): https://whitemarketpeptides.com/shop/xxxxx
Key takeaway: Ipamorelin is best understood as a short-acting, GH-selective pulse tool via GHSR-1a, useful for research questions where timing and endocrine selectivity matter. Educational content only; no medical advice.
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