The cleanest GHRP ever made — triggers a natural GH pulse without the cortisol, prolactin, or hunger spikes that plague older growth-hormone peptides.
Ipamorelin is a synthetic pentapeptide that selectively activates the ghrelin (growth hormone secretagogue) receptor to trigger natural GH release. It was developed by Novo Nordisk in the 1990s specifically to isolate the GH-releasing effect from the unwanted hormonal side effects of older GHRPs.
Unlike GHRP-2 or GHRP-6, ipamorelin does not meaningfully raise cortisol, prolactin, or ACTH — and it does not cause the strong hunger spikes that earlier GHRPs are known for. That claim rests on one specific finding in Raun 1998 (PMID 9849822): in swine, ipamorelin failed to raise ACTH or cortisol above GHRH-stimulation levels even at doses more than 200 times the ED50 for GH release, while GHRP-6 and GHRP-2 both raised them. This selectivity is its main advantage, and it is an animal finding — no human study has compared ipamorelin head-to-head against another GHRP on cortisol.
Development history matters here too. Novo Nordisk took ipamorelin into a Phase 2 trial for post-operative ileus, and it missed its primary endpoint (Beck 2014, PMID 25331030). Development stopped there. It is not approved for any human use anywhere.
Not FDA approved. WADA prohibited (S2 — Peptide Hormones). Available as a research chemical.
Binds the ghrelin receptor on the pituitary and triggers a natural GH pulse. Unlike older GHRPs, it does not activate the HPA axis — so cortisol and prolactin stay near baseline.
When paired with a GHRH analog like CJC-1295 or sermorelin, ipamorelin amplifies the pulse several-fold — which is why the CJC+Ipa stack is so popular. Alone, the pulse is smaller but still meaningful.
Stimulates your own GH production rather than replacing it, so natural feedback loops stay intact — unlike exogenous HGH.
Worth separating what is measured from what is reported, because for ipamorelin the gap is wide.
| Claim | What actually backs it |
|---|---|
| Releases GH in humans | Measured. Gobburu 1999 (PMID 10496658), 40 healthy men, dose-proportional GH release peaking at 0.67 h. |
| Does not raise cortisol or prolactin | Measured, in animals. Raun 1998 (PMID 9849822), swine, at 200× the GH ED50. |
| Safe over about a week | Measured. Beck 2014 (PMID 25331030), 114 surgical patients, IV twice daily up to 7 days, well tolerated. |
| Builds bone | Rats only. Three studies, below. No human bone data. |
| Sleep quality | Not measured for ipamorelin. Consistent with GH physiology and the most consistent user report, but no trial has tested it. |
| Body composition, recovery, skin | Not measured. No human trial has assessed any of these for ipamorelin. |
The pattern is worth stating plainly: the effects people take ipamorelin for are the ones with no human evidence, and the effects with human evidence are pharmacological readouts rather than outcomes.
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Start Tracking FreeThe paper that named ipamorelin "the first selective growth hormone secretagogue", and the origin of essentially every claim made about this compound.
In rat pituitary cells ipamorelin released GH with potency and efficacy close to GHRP-6 (EC50 1.3 vs 2.2 nmol/L). In conscious swine, ED50 2.3 nmol/kg with Emax 65 ng/mL, again similar to GHRP-6 (3.9 nmol/kg, 74 ng/mL); GHRP-2 was more potent but reached a lower peak. None of the secretagogues tested altered FSH, LH, prolactin or TSH. The decisive result: GHRP-6 and GHRP-2 both raised ACTH and cortisol, and ipamorelin did not — even above 200× the ED50 for GH release.
Limits. Swine and rats. Acute dosing. No human comparison exists.
A dose-escalation study across five 15-minute intravenous infusion rates (4.21 to 140.45 nmol/kg), eight healthy men at each level, 40 in total.
| Terminal half-life | 2 hours |
| Clearance | 0.078 L/h/kg |
| Volume of distribution (steady state) | 0.22 L/kg |
| GH peak | 0.67 hours (about 40 minutes) |
| SC50 for half-maximal GH release | 214 nmol/L |
| Maximal GH production rate | 694 mIU/L/h |
GH release was a single episode at every dose, declining exponentially to negligible. Note what this study reports: an infused rate and a plasma concentration. It never establishes a subcutaneous microgram dose, which is what everyone actually injects.
Phase 2, multicentre, double-blind, placebo-controlled (NCT00672074). 117 enrolled, 114 analysed, all undergoing open or laparoscopic bowel resection. Ipamorelin 0.03 mg/kg intravenously twice daily from post-operative day 1 through day 7 or discharge.
It missed. Median time to first tolerated solid meal was 25.3 hours on ipamorelin versus 32.6 hours on placebo, p = 0.15. The authors report no significant difference on the key or any secondary efficacy endpoint, and development was discontinued.
The trial still matters, for two reasons. It is the source of the only real human safety data on ipamorelin — treatment-emergent adverse events occurred in 87.5% of the ipamorelin group versus 94.8% of placebo, and the drug was well tolerated. And it is the longest published human exposure that exists: seven days. Anyone running 12 to 16 week protocols is well past the edge of the evidence.
Three separate rat studies, consistent with each other and untested in humans.
Lu 2024 (PMID 39043357) found ipamorelin and anamorelin inhibited cisplatin-induced weight loss in ferrets, by roughly 24% during the delayed 48–72 hour phase. An animal study, but it points at the muscle-wasting application the ghrelin-agonist class keeps being investigated for.
Not medical advice. These figures describe what is reported in the literature and what practitioners and communities do — not a recommendation, and for most compounds here no human dose-finding study exists. Talk to a qualified healthcare provider.
The human pharmacokinetic study (Gobburu, PMID 10496658) dosed intravenously in 40 healthy male volunteers and reports a plasma concentration — an SC50 of 214 nmol/L for half-maximal GH release — not a syringe amount. The post-operative ileus trial used 0.03 mg/kg intravenously. No human dose-finding study exists for the subcutaneous microgram protocols below.
Combined with CJC-1295 (100 mcg) or sermorelin (200–500 mcg) pre-bed to amplify the pulse. This is the standard modern growth-hormone peptide protocol. See the CJC-1295 + Ipamorelin guide for full details.
100–300 mcg is the effective range. More than 300 mcg produces diminishing returns; the pituitary’s pulse ceiling is reached quickly. For more total GH exposure, add pulses (up to 3 daily), not bigger per-dose amounts.
Several clinics prescribe it. Nothing supports it. The desensitisation data people are reaching for is Rahim and Shalet's hexarelin study (PMID 10990150), where twice-daily dosing for 16 weeks cut the GH response by about 45% — and four weeks off restored it fully. That is a timescale of months on and a month off, borrowed from a different compound. Two days a week does not map onto it in either direction.
Pre-filled with a typical Ipamorelin setup. Edit any field — the draw updates live.
Insulin syringe — 100 units = 1 mL
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Not medical advice. These figures describe what is reported in the literature and what practitioners and communities do — not a recommendation, and for most compounds here no human dose-finding study exists. Talk to a qualified healthcare provider.
5 mg vial + 2.5 mL BAC water = 2 mg/mL = 2000 mcg/mL
| Dose | Volume | Syringe Units |
|---|---|---|
| 100 mcg | 0.05 mL | 5 units |
| 200 mcg | 0.10 mL | 10 units |
| 300 mcg | 0.15 mL | 15 units |
5 mg vial at 200 mcg 2×/day = ~12 days
Ipamorelin has one of the cleanest side-effect profiles of any GHRP — that’s the whole point, and it is better evidenced than most claims here. But note the ceiling: the longest published human exposure is seven days (Beck 2014, PMID 25331030, where 87.5% of the ipamorelin group had a treatment-emergent adverse event versus 94.8% on placebo). There is no long-term human safety data for ipamorelin at all.
Ipamorelin is sold for research use only. If you are sourcing it for research, we recommend Lyvn — every batch third-party tested with the full laboratory panel published on the product page.
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For research use only. Not for human consumption. 21+.
Build your protocol, log every dose, monitor your body's response, and get reminders so you never miss a dose.
Start Tracking FreeNo. Ipamorelin has never been approved as a drug. Helsinn took it to Phase 2 for post-operative ileus and discontinued development.
Community-practice dosing is 100–300 mcg per injection, typically 1–3 times daily — most commonly before bed (to amplify the overnight GH pulse) and optionally pre-workout or fasted morning. The 100 mcg single-pulse figure approximates a saturating dose at the GHSR-1a receptor based on class-pharmacology extrapolation, not a peer-reviewed dose-response study in humans.
A typical reconstitution is 5 mg of ipamorelin + 2 mL of bacteriostatic water, yielding 2.5 mg/mL. A 200 mcg dose draws to 0.08 mL (8 units on a 100-unit insulin syringe). Many users dilute further (5 mg + 2.5 mL = 2 mg/mL) so a 100 mcg dose is exactly 5 units — easier to measure on small syringes.
Ipamorelin (a GHRP / GHSR-1a agonist) and CJC-1295 (a GHRH analog) act on two different growth-hormone-axis receptors, and stacking them produces a synergistic GH pulse larger than either alone. This combination is the most popular community GH-peptide stack. Both compounds individually lack human RCT efficacy data; the combination has no published human trial.
Approximately 2 hours, supporting the pulsatile multiple-daily-dose protocol. Ipamorelin produces a brief permission window at the somatotroph that clears between doses — preserving the somatostatin trough architecture that is thought to keep GH signaling physiological rather than tonic.
Yes. Ipamorelin is prohibited at all times under WADA S2.2 (Growth Hormone Secretagogues). No therapeutic-use exemption available.
Disclaimer: This guide is for educational and informational purposes only and is not intended as medical advice, diagnosis, or treatment. The compounds discussed are not FDA approved for human use. Always consult a qualified healthcare provider before starting any new supplement or peptide protocol. StackTrax does not sell peptides or supplements directly — purchase links go to third-party vendors. StackTrax is not responsible for the products, quality, or business practices of any third-party vendor.
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StackTrax guides cover peptides and compounds that are not FDA-approved for the uses discussed. The dosing, reconstitution, and safety information is compiled from published research and community protocols for educational purposes only.
Before using any compound mentioned here, consult a qualified healthcare provider. StackTrax does not sell, prescribe, or recommend these substances for personal use.