Ipamorelin
A selective growth-hormone-releasing peptide studied for its ability to stimulate the body’s own GH release with relatively few off-target effects. Popular for recovery and body composition, but not an approved drug.
Quick take
- What it is: a synthetic peptide that selectively stimulates the pituitary to release growth hormone.
- What people use it for: recovery, body composition, and sleep, by nudging natural GH release.
- What we actually know: it reliably raises GH short-term in studies; long-term human outcome data is limited.
- Status: not FDA-approved and banned in competitive sport.
What it is
Ipamorelin is a synthetic peptide classified as a growth-hormone secretagogue. It mimics the hormone ghrelin and acts on the pituitary gland to stimulate release of the body’s own growth hormone (GH). It is often described as relatively selective, meaning it raises GH with comparatively little effect on other hormones such as cortisol and prolactin.1
How it works
Rather than supplying growth hormone directly, Ipamorelin binds the ghrelin/GH-secretagogue receptor and prompts the pituitary to release GH in a more pulse-like, natural pattern.1,2 This mechanism is the basis for its popularity as a “gentler” alternative to injected growth hormone.
What the evidence shows
Short-term studies confirm that Ipamorelin and similar secretagogues do raise growth-hormone levels. What is far less established is whether this produces meaningful long-term benefits for recovery, body composition or aging in humans, and what the long-term safety looks like.2 Much of the popular use rests on short-term physiology plus anecdote.
Dosages reported in the literature
Informational only. The figures below describe doses reported in research and clinical settings. They are not a recommendation or a prescription, and appropriate use should be determined by a qualified healthcare professional.
| Setting | Route | Reported range |
|---|---|---|
| Research / clinical | Subcutaneous | Reported in low microgram-per-kilogram amounts |
| Anecdotal / clinic-reported | Subcutaneous | Commonly ~100–300 mcg, one to several times daily |
Reported protocols vary and are not supported by long-term outcome trials.
Safety & side effects
Reported short-term side effects include injection-site reactions, headache, flushing and water retention. Because there are no long-term controlled human studies of the popular uses, the long-term risk profile is not well characterized. As with all peptides from the unregulated market, product purity and dose accuracy vary between sources.
Legal & regulatory status
Ipamorelin is not approved by the FDA for any use. It is banned in competitive sport — the World Anti-Doping Agency prohibits growth-hormone secretagogues at all times (category S2).3 Rules vary by country and change over time.
References
- Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology. 1998 Nov;139(5):552-561. [PMID 9849822, doi:10.1530/eje.0.1390552]
- Ishida J, Saitoh M, Springer J, et al. Growth hormone secretagogues: history, mechanism of action, and clinical development. JCSM Rapid Communications. 2020;3(1):25-37. [doi:10.1002/rco2.9]
- World Anti-Doping Agency. The 2026 Prohibited List. Section S2.2 (Growth Hormone (GH), its fragments and releasing factors / GH secretagogues), which lists ipamorelin. World Anti-Doping Agency; effective 1 January 2026. [wada-ama.org]