Ipamorelin
Ipamorelin Acetate
A ghrelin-mimicking peptide studied for growth hormone release, with limited human data
Ipamorelin is a synthetic five-amino-acid peptide that acts as a growth hormone secretagogue: it binds the ghrelin receptor in the pituitary gland and prompts release of the body's own growth hormone (GH). In 1998 swine studies it raised GH without raising cortisol, which is why it's often called selective, but human data on selectivity are limited. The human evidence is thin overall. One IV study in 48 healthy men found dose-linear GH release and a half-life of about 2 hours. A Phase 2 trial in 117 adults recovering from abdominal surgery missed its primary endpoint, and development stopped. No trial has measured muscle, fat-loss or anti-aging outcomes. As of October 2026 it isn't approved as a drug anywhere, and this product is sold for research use only.
Read the research profile for mechanisms, citations, and safety context before comparing vendors. View the Ipamorelin research profile.
Key Benefits
Mechanism of Action
Ipamorelin mimics ghrelin and binds the growth hormone secretagogue receptor (GHSR) on pituitary cells, which triggers a short burst of GH release. In the IV study in healthy men, the GH peak rose with the dose, and GH fell back to very low levels at every dose within 6 hours. Its reputation for selectivity comes from animal work. In conscious swine, GHRP-6 and GHRP-2 raised ACTH and cortisol while ipamorelin didn't, even at more than 200 times the dose needed for GH release, and none of the compounds tested changed prolactin (Raun et al., 1998). Users commonly report less hunger than with GHRP-6, though we found no human study that measured appetite with ipamorelin.
Dosing Guidelines
Typical Dose
200-300 mcg
Frequency
2-3x daily
Duration
8-12 weeks
Note: These figures match vendor guidance, not a trial. Users commonly report subcutaneous injection on an empty stomach (no food for about 30 minutes before and after), with the main dose before bed to match the overnight GH pulse; no study has tested that timing. Some add doses on waking and mid-afternoon, while many take one bedtime dose of 100-300 mcg with Mod GRF 1-29 (CJC-1295 without DAC). The trials gave ipamorelin by IV infusion, dosed by body weight: 4.21-140.45 nmol/kg over 15 minutes in healthy men, and 0.03 mg/kg twice daily for up to 7 days after surgery in the Phase 2. As of October 2026, WADA prohibits ipamorelin at all times (S2.2.4).
Research & Studies
How a GHRH analogue and a GHRP act on different pituitary receptors, and why users often combine them.
Read Full ResearchHub page on peptides studied or used for fat loss. No trial has measured fat loss with ipamorelin.
Read Full ResearchHow the doses and timings users report compare with what trials actually tested.
Read Full ResearchWhat is and isn't known about the long-term safety of growth hormone secretagogues, including ipamorelin.
Read Full ResearchPotential Side Effects
Reported side effects may include:
- - Water retention, usually temporary (user reports)
- - Tingling or numbness in hands and feet (user reports)
- - Mild headaches, mostly early on (user reports)
- - Drowsiness, especially with bedtime doses (user reports)
- - More low potassium, high blood sugar and insomnia than placebo (post-surgery Phase 2 trial)
- - 2 deaths in that trial's ipamorelin group after treatment ended; causality unclear (FDA, 2024)
- - Human data cover single doses and up to 7 days of IV use; FDA's 2024 review found no published animal toxicity studies
This information is for research purposes only. Always consult with a healthcare professional.
Popular Stacking Options
Ipamorelin + CJC-1295 (no DAC)
Users commonly pair ipamorelin with Mod GRF 1-29, a short-acting GHRH analogue that acts on a different pituitary receptor, expecting a larger GH release from the two together. Users commonly report 100-300 mcg of each, often at bedtime. No controlled human trial has tested the combination.
Shop this stackIpamorelin + BPC-157
Some users pair them for injury recovery. BPC-157's tissue-repair data come mostly from rodent studies, and ipamorelin has no trial data on recovery. No study has tested the combination, and as of October 2026 neither is approved as a drug.
Shop this stackIpamorelin + Tesamorelin
Some users add tesamorelin for abdominal fat. Tesamorelin is an FDA-approved prescription medicine (Egrifta) for excess abdominal fat in adults with HIV-associated lipodystrophy, and research-use versions aren't equivalent to it. No study has tested it with ipamorelin.
Shop this stackFrequently Asked Questions
When is the best time to take Ipamorelin?
No study has tested timing for ipamorelin. Users commonly report taking it on an empty stomach, with no food for about 30 minutes before and after, on the idea that food blunts GH release. Bedtime is the most common timing in user reports, chosen to coincide with the large natural GH pulse in early sleep, and some add a dose on waking. The human trials gave it by IV infusion, so they offer no guidance on the timing of subcutaneous doses.
How does Ipamorelin compare to HGH injections?
Ipamorelin prompts the pituitary to release the body's own GH rather than supplying the hormone from outside. In the IV study in healthy men, GH returned to very low levels within 6 hours of a dose. Vendor copy often claims this makes it safer than GH injections and that it doesn't suppress natural production, but we found no study that compared the two or measured natural GH output after repeated use. Prescription growth hormone is an FDA-approved medicine, while ipamorelin isn't approved anywhere as of October 2026. In a post-surgery Phase 2 trial, the ipamorelin group had more low potassium, high blood sugar and insomnia than the placebo group. Talk to a healthcare professional before using any compound that changes hormone levels.
Will Ipamorelin make me hungry?
Users commonly report little or no extra hunger with ipamorelin, unlike GHRP-6, which users often describe as causing intense hunger soon after injection. Both act on the ghrelin receptor, and ghrelin is the body's main hunger hormone, so the difference is notable. We couldn't find a human study that measured appetite with ipamorelin, so this rests on user reports.
How long until I see results from Ipamorelin?
There's no tested timeline, because no trial has measured sleep or body composition with ipamorelin. Vendor and community guides claim better sleep within the first week and body-composition changes after 4-8 weeks alongside diet and training. These are self-reports, often from people also using Mod GRF 1-29, and we couldn't find a study that measured either. Clinicians at FDA's 2024 advisory meeting also said their patients report better sleep, which is anecdote rather than trial data.
More from this category
Compare nearby options in the same category before choosing a research product.
CJC-1295
A long-acting GHRH analogue studied in small 2006 human trials for raising growth hormone and IGF-1.
GHRP-2
A ghrelin-mimetic secretagogue studied for its strong effect on growth hormone release.
GHRP-6
A ghrelin mimetic studied for growth hormone release, with strong appetite effects reported by users.
Hexarelin
A ghrelin-mimetic GH secretagogue studied for growth hormone release and short-term heart effects.
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