Hexarelin
Also known as: Examorelin
Among the most potent growth-hormone releasing peptides studied — and the one with the best-documented tendency to stop working as the receptor desensitises.
What it is
Hexarelin, also called examorelin, is a synthetic growth-hormone releasing peptide of the same family as GHRP-6 and GHRP-2. It is among the most potent at triggering a growth-hormone pulse, and it was investigated as a medicine — including for cardiac indications — without ever being approved.
Composition
A six-amino-acid synthetic peptide. What is sold online is a research chemical.
Proposed mechanism
It binds the growth-hormone secretagogue receptor to produce a growth-hormone pulse. Separately, there is research interest in direct effects on cardiac tissue that appear to be independent of growth hormone, acting through a different receptor found in the heart.
Claimed benefits
Muscle gain, fat loss, tissue repair, and cardiac protection.
What the evidence shows
Silver· human data. Hexarelin reliably raises growth hormone, and does so more strongly than most of its class. The problem is documented in the human literature rather than merely rumoured: the response diminishes measurably with continued use as the receptor downregulates. It is the clearest case in this class of a compound whose effect erodes precisely as you keep taking it.
The cardiac research is genuinely interesting and mostly animal work. It is a research question, not an established benefit, and it is not why anyone buys it.
Legal & regulatory status
Not a licensed medicine. Prohibited at all times in sport under the WADA list as a growth-hormone secretagogue.
Known risks & unknowns
Raised cortisol and prolactin, water retention, increased appetite, and reduced insulin sensitivity. Long-term safety in healthy adults is unstudied, and the desensitisation means any effect is self-limiting.
Sources
Frequently asked questions
- What is hexarelin?
- A synthetic growth-hormone releasing peptide of the same family as GHRP-6 and GHRP-2, and one of the most potent at triggering a growth-hormone pulse. It was investigated as a medicine, including for cardiac indications, but was never approved.
- Why is desensitisation a problem with hexarelin?
- Its potency comes at a cost: the growth-hormone response to hexarelin falls off measurably with continued use as the receptor downregulates, and this is documented in human studies rather than merely reported anecdotally. It is the clearest example in this class of an effect that diminishes precisely as you keep using it.
- Does hexarelin have benefits beyond growth hormone?
- There is genuine research interest in direct cardiac effects that appear independent of growth hormone, mostly from animal work and small human studies. That is a research question, not an established benefit, and it is not why anyone buys it.
- Is hexarelin banned in sport?
- Yes — growth-hormone secretagogues are prohibited at all times under the WADA list.
Related compounds
- GHRP-6 (Unproven)
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.
- GHRP-2 (Silver)
An evidence-tiered explainer on GHRP-2 (pralmorelin): a growth-hormone releasing peptide that reliably raises GH — and why raising GH is not the same as changing your body.
- Ipamorelin (Unproven)
An evidence-tiered explainer on ipamorelin: a synthetic growth-hormone secretagogue marketed for muscle, fat loss and anti-ageing, whose real-world fitness benefits in healthy people are unproven.
- Sermorelin (Silver)
An evidence-tiered explainer on sermorelin: a growth-hormone-releasing hormone analogue with a genuine medical history, now marketed for anti-ageing and muscle on evidence that doesn't support those claims.
Written and reviewed by Mathew Beale, MSc Biotechnology, University of Reading.
Last reviewed: