With another GH/IGF-axis medicine
Safety flag
Duplicate GH/IGF-axis stimulation may amplify IGF-1 elevation, edema, joint symptoms, and glucose intolerance.
Interaction evidence source All research profiles
Investigational GH secretagogue
Hexarelin
Prepared by the ezGLP team. Sources last checked . Profile reviewed .
Also known as Examorelin
Routes represented in the knowledgebase: Subcutaneous (SubQ).
Educational overview
Not FDA-approved for human use in the U.S.; human physiology studies do not establish long-term wellness benefit or safety.
Hexarelin, also called examorelin, is a synthetic hexapeptide analogue of GHRP-6 in which a methylated tryptophan residue improves stability and potency. It belongs to the growth hormone-releasing peptide family and acts as an agonist at the ghrelin receptor GHS-R1a in the pituitary and hypothalamus, producing a pronounced but short-lived pulse of growth hormone. Hexarelin also binds CD36, a scavenger receptor expressed in heart and vascular tissue, which is the basis for the cardioprotective effects reported in animal models. Like other ghrelin mimetics, it raises prolactin, ACTH, and cortisol acutely, and it is regarded as one of the more potent GHRPs per unit mass.
Human evidence comes from small physiology studies conducted mainly by Italian and British endocrine groups in the 1990s. Ghigo and colleagues in 1994 compared intravenous, subcutaneous, intranasal, and oral routes in healthy adults; Arvat and colleagues in 1995 and 1997 examined how other hormones modulate its GH-releasing activity and its effects on prolactin, ACTH, and cortisol; Massoud and colleagues published a dose-response study in 1996; and Rahim and colleagues reported in 1998 that repeated administration over sixteen weeks in healthy elderly adults was followed by partial attenuation of the GH response. No controlled trial has tested hexarelin for any clinical outcome, and long-term safety in humans is unknown.
Hexarelin is not approved as a medicine by the FDA, the EMA, or comparable regulators anywhere, and development for clinical indications was abandoned after the physiology studies. In the United States it circulates only as a compounded or research-labelled peptide; unlike GHRP-2, GHRP-6, and ipamorelin, it is not named on the FDA's published list of bulk substances that may present significant safety risks, though it also does not appear on any list of substances permitted for compounding. The World Anti-Doping Agency names examorelin (hexarelin) explicitly on its Prohibited List under section S2.2.4, growth hormone-releasing factors, banned at all times.
The compound is generally supplied as a lyophilised powder that is reconstituted with bacteriostatic or sterile water for subcutaneous injection; intranasal and oral routes were studied in 1994 but showed much lower bioavailability. With no approved label, the supplier's documentation is the only formal reference for storage temperature and beyond-use dating, and published stability data for reconstituted solutions are lacking. Because the 1998 desensitisation study showed the GH response can fade with continuous exposure, dose logs for hexarelin often record start and stop dates alongside the usual lot number, reconstitution date, concentration, and storage conditions, so that any change in response can be related to duration of exposure.
- Category
- Investigational GH secretagogue
- Routes represented
- Subcutaneous (SubQ)
- Storage context
- Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.
Published literature
No verified PubMed or DOI link is available for this entry.
Safety evidence
Serious or important: peptide immunogenicity, aggregation, or impurity concerns.
Route-specific human safety and long-term adverse effects are not established.
Safety evidence sourceInteraction evidence
These are general, pairwise evidence notes. Green identifies the potential-synergy category, while Lv3/Lv2/Lv1 communicates evidence strength; it does not guarantee benefit or cancel a safety warning.
Common questions
Is hexarelin FDA approved?
No. Hexarelin has never received marketing approval from the FDA or from any other national regulator, and no company is known to be developing it for a clinical indication. It is available in the United States only as a compounded or research-use peptide. The FDA has not published a specific safety-risk determination for hexarelin as it has for GHRP-2, GHRP-6, and ipamorelin, but it likewise has not been placed on any list of substances eligible for compounding.
What is the difference between hexarelin and GHRP-6?
Hexarelin is a structural analogue of GHRP-6 with a 2-methyl-D-tryptophan substitution that increases stability and potency. In comparative human studies hexarelin produced a larger growth hormone peak, and it shares GHRP-6's acute effects on prolactin, ACTH, and cortisol. Hexarelin also binds the CD36 receptor, which underlies cardioprotective findings in animal models that GHRP-6 does not share to the same degree. Neither peptide has an approved indication.
Does hexarelin stop working over time?
Human data suggest partial attenuation. Rahim and colleagues reported in 1998 that after sixteen weeks of repeated hexarelin administration in healthy elderly adults, the growth hormone response to the peptide was reduced, although it partially recovered after a washout period and the response to GHRH was preserved. This desensitisation phenomenon has been described for several ghrelin-receptor agonists and is one reason their long-term effects are uncertain.
Is hexarelin banned by WADA?
Yes. The World Anti-Doping Agency Prohibited List names examorelin (hexarelin) as an example of a growth hormone-releasing peptide under section S2.2.4, together with GHRP-2, GHRP-6, and related compounds. Substances in section S2 are prohibited at all times, in and out of competition, and are treated as non-specified substances. WADA-accredited laboratories have published detection methods for GHRPs in urine.
Further reading
- Ghigo et al., J Clin Endocrinol Metab 1994 (hexarelin GH-releasing activity after IV, SC, intranasal, and oral routes)
- Arvat et al., Neuroendocrinology 1995 (modulation of hexarelin GH-releasing activity in man)
- Massoud et al., J Clin Endocrinol Metab 1996 (hexarelin-induced GH, cortisol, and prolactin release dose-response)
- Rahim et al., Growth Horm IGF Res 1998 (does desensitisation to hexarelin occur?)
- Sigalos & Pastuszak, Sex Med Rev 2018 (safety and efficacy of growth hormone secretagogues)
- World Anti-Doping Agency, The Prohibited List (section S2.2)
Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.
For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live. Consult a licensed healthcare professional.