Hexarelin Side Effects: GH Secretagogue Investigated but Not Approved
Hexarelin is a synthetic hexapeptide growth hormone secretagogue developed in the 1990s. It is not approved by the FDA or TGA for any therapeutic indication. Published clinical research describes effects on growth hormone, cortisol, and the cardiovascular system, but also pituitary desensitisation with continued dosing. WADA prohibits its use in sport.
Hexarelin is approved in some jurisdictions but not in others. Investigational. Not FDA- or TGA-approved. Published research describes pituitary desensitisation with continued dosing. WADA prohibits competitive use. This page summarises the published literature and regulator positions. It is not medical advice.
Key Takeaways
- Hexarelin is an investigational growth hormone secretagogue. Not FDA- or TGA-approved.
- Published research reports pituitary desensitisation with continued dosing, alongside expected GH-axis effects.
- Direct cardiovascular effects beyond GH-mediated effects have been described in animal and human studies.
- WADA prohibits hexarelin in competitive sport.
- Long-term human safety is not characterised.
What is Hexarelin, and what is it marketed for?
Hexarelin (His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2). Hexarelin is a ghrelin/GHS-R agonist that stimulates pulsatile growth hormone release from the pituitary. Published research also describes cardiovascular effects independent of GH, possibly via direct receptor activity on cardiac tissue.
What side effects and safety concerns have been reported?
The summary below draws from the published literature and regulator statements. Severity classification follows the source documents.
| Concern | What has been reported | Source |
|---|---|---|
| Pituitary desensitisation | Sustained dosing reduces the GH response over time per published trials | Common to GH-secretagogue peptides |
| Cortisol and prolactin | Modest increases reported in trials | Common to GH-secretagogues |
| Cardiovascular effects | Trial data describe direct cardiovascular effects in addition to GH-mediated effects | Mechanistic concern, not a regulator-cleared therapeutic use |
| WADA prohibited | Listed under WADA prohibited substances (S2 anabolic agents) | Use in competitive sport is prohibited |
| Long-term safety | Not characterised in long-term human use | All trial data are short-duration |
Taking Hexarelin alongside prescription medicines?
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Common Questions About Hexarelin
No. Hexarelin is investigational and not approved by the FDA, EMA, or TGA for any therapeutic use.
Published studies describe progressive pituitary desensitisation with continued hexarelin dosing, which reduces the GH response over time. This is part of the reason it has not progressed to long-term clinical use.
Yes. WADA prohibits hexarelin under section S2 of the prohibited list (anabolic agents).
Published research has described direct cardiovascular effects of hexarelin independent of growth hormone, including effects on cardiac function in animal models. The clinical significance of these effects in unsupervised human use is not characterised.
References
- Imbimbo BP et al. Growth hormone-releasing activity of hexarelin in humans. Eur J Clin Pharmacol. 1994;46:421-425. Source.
- Ghigo E et al. Hexarelin and the regulation of GH secretion. Endocrine. 2001. Source.
- World Anti-Doping Agency. WADA Prohibited List. Source.
- U.S. Food & Drug Administration. FDA position on bulk drug substances for compounding. Source.