Ipamorelin
Also known as: Growth-hormone secretagogue
Prompts a short-lived rise in growth hormone — but that this translates into muscle, fat loss or anti-ageing benefits in healthy people is unproven.
What it is
Ipamorelin is a synthetic peptide that prompts the body to release a pulse of its own growth hormone. It is often marketed as a "cleaner" secretagogue because it has little effect on appetite or the stress hormone cortisol, unlike some older peptides in its class.
Composition
It is a short synthetic peptide that mimics ghrelin — the hunger hormone — at the pituitary, where it triggers growth-hormone release. What is sold online is a laboratory-made research chemical.
Proposed mechanism
By acting on the ghrelin receptor, it stimulates the pituitary to secrete a burst of growth hormone, which the marketing links to muscle gain, fat loss and "anti-ageing".
Claimed benefits
More muscle, less fat, better recovery and slowed ageing.
What the evidence shows
Marketing claim· mixed evidence. Raising growth hormone is real pharmacology, but that does not automatically produce meaningful muscle gain or fat loss in healthy adults. There are no good long-term human trials demonstrating the physique or anti-ageing benefits it is sold for, so those claims are not supported.
Legal & regulatory status
Not an approved medicine for muscle-building or anti-ageing use, and sold as a research chemical with no quality control. Growth-hormone secretagogues are explicitly named on the WADA Prohibited List and are banned in sport at all times.
Known risks & unknowns
Its long-term safety in healthy people is not established, and research-chemical products carry additional purity and contamination risks. Sustained manipulation of the growth-hormone axis has theoretical long-term risks that have not been well characterised for this compound.
Sources
Frequently asked questions
- What is ipamorelin?
- It is a synthetic peptide that mimics the hunger hormone ghrelin, prompting the pituitary to release a pulse of growth hormone. It is often marketed as a 'cleaner' secretagogue because, unlike some older peptides in its class, it has little effect on appetite or the stress hormone cortisol.
- Does ipamorelin build muscle or burn fat?
- Raising growth hormone is real pharmacology, but that does not automatically produce meaningful muscle gain or fat loss in healthy adults. There are no good long-term human trials showing the physique or anti-ageing benefits it is sold for, so those claims are not supported.
- Is ipamorelin safe?
- Its long-term safety in healthy people is not established, and products sold as 'research chemicals' carry additional purity and contamination risks. It is not an approved medicine for muscle-building or anti-ageing use.
- Is ipamorelin banned in sport?
- Yes. Growth-hormone secretagogues are explicitly named on the WADA Prohibited List and are banned at all times, in and out of competition.
Related compounds
- CJC-1295 — Marketing claim
An evidence-tiered explainer on CJC-1295: a long-acting growth-hormone-releasing hormone analogue marketed for muscle and anti-ageing, with only early pharmacology data and no proven fitness benefits.
- GHRP-6 — Marketing claim
An evidence-tiered explainer on GHRP-6: an older growth-hormone-releasing peptide known for strongly stimulating appetite, marketed for muscle on evidence that doesn't establish real-world benefit.
- MK-677 (Ibutamoren) — Preliminary
An evidence-tiered explainer on MK-677 (ibutamoren): an oral ghrelin-receptor agonist — technically not a peptide — that raises GH and IGF-1, with real but modest human trial data and no approval.
- Tesamorelin — Well-supported
An evidence-tiered, non-promotional explainer on tesamorelin (Egrifta): a GHRH analogue, the one GH-releasing peptide with FDA approval and robust trial data — for a specific medical use, not fitness.
Written and reviewed by Mathew Beale — MSc Biotechnology, University of Reading.
Last reviewed: