← All compounds · evidence tier first, by design
| Use | E1 | E2 | E3 | E4 | E5 | E6 | E7 | E8 |
|---|---|---|---|---|---|---|---|---|
| E3 Growth hormone release | E3 | |||||||
| E4 Muscle mass and body composition | E4 | |||||||
| E4 Short stature in children | E4 |
Hexarelin
Synthetic hexapeptide His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2, an analogue of GHRP-6 with a methylated D-tryptophan; contains D-amino acids and a C-terminal amide, so no standard one-letter sequence is given.
Non-standard residues or modifications: no plain one-letter sequence
Also: Examorelin
A synthetic six-amino-acid growth hormone secretagogue, a close analogue of GHRP-6, that acts on the ghrelin receptor to release growth hormone. It was studied in human endocrine experiments and small clinical studies in the 1990s, including in children with short stature and in adults over 16 weeks, but was never approved as a medicine in any jurisdiction checked. WADA lists it under the name examorelin. It is sold online as a research chemical with claims of raising growth hormone and muscle mass.
- US C gray market
- EU C gray market
- UK ? not verified
- CA C gray market
- AU ? not verified
- JP ? not verified
- CN ? not verified
01Regulatory status, by jurisdiction
| Jurisdiction | Status | Detail and primary source |
|---|---|---|
| US | Not approved | No FDA-approved application: openFDA Drugs@FDA returns no application with a hexarelin active ingredient (query: products.active_ingredients.name:HEXARELIN*; EXAMORELIN* also returned none). Hexarelin does not appear in Category 1, 2 or 3 of FDA's 503A bulk drug substances nomination list (updated 14 May 2026). openFDA states its data are unvalidated.“No matches found!”openFDA Drugs@FDA API (FDA) · retrieved 2026-10-10 |
| EU | Not approved | No product containing hexarelin or examorelin appears in EMA's downloadable medicines dataset (generated 10 Oct 2026), which covers centrally authorised medicines, refusals and withdrawn applications. National authorisations were not checked individually.“This includes information on marketing authorisations of centrally authorised medicines and post-authorisation procedures.”Download medicine data | European Medicines Agency (EMA) · retrieved 2026-10-10 |
| CA | Not approved | Queries of Health Canada's Drug Product Database API for the active ingredients hexarelin and examorelin, and for the brand name hexarelin, returned no products on the retrieval date.“Search by drug identification number”Drug Product Database online query · retrieved 2026-10-10 |
| UK AU JP CN | Not yet verified from a primary source. No status is shown rather than an unsourced one. | |
Sport (WADA): Prohibited · class S2.2.4. Named, as examorelin (hexarelin), under S2.2.4 growth hormone releasing factors, prohibited at all times. “GH-releasing peptides (GHRPs) [e.g. alexamorelin, examorelin (hexarelin), GHRP-1, GHRP-2 (pralmorelin), GHRP-3, GHRP-4, GHRP-5 and GHRP-6]” WADA source
02What the human evidence shows
Growth hormone release
n/c: not counted here; see the cited review.
Numerous small human pharmacology studies, many randomised and placebo-controlled with crossover designs, show that hexarelin acutely raises blood growth hormone after intravenous, subcutaneous, intranasal or oral administration, alongside rises in prolactin, ACTH and cortisol. In adults given hexarelin twice daily for 16 weeks the growth hormone response was partly and reversibly attenuated, and IGF-I did not change significantly. The number of such studies was not counted, so both counts are left blank.
- [1] Acute growth hormone release in humans after intravenous, subcutaneous, intranasal and oral administration
- [2] Dose-dependent growth hormone, prolactin and cortisol release after intravenous hexarelin in healthy adult men
- [3] Partial, reversible attenuation of the growth hormone response over 16 weeks in adults, with no significant change in IGF-I
Registered-study counts: ClinicalTrials.gov intervention search “hexarelin”, fetched 2026-10-10. Registered studies include trials of other uses; the gap between registered and reported is itself a finding.
Muscle mass and body composition
n/c: not counted here; see the cited review.
The only adult study identified that measured body composition was an uncontrolled 16-week study: total body fat, lean body mass and bone mineral density did not change significantly from baseline. No randomised trial of muscle mass, strength or body composition was identified.
- [3] No significant change in total body fat, lean body mass or bone mineral density after 16 weeks in adults
Registered-study counts: ClinicalTrials.gov intervention search “hexarelin”, fetched 2026-10-10. Registered studies include trials of other uses; the gap between registered and reported is itself a finding.
Short stature in children
n/c: not counted here; see the cited review.
An uncontrolled study gave intranasal hexarelin to 8 prepubertal children with short stature for up to 8 months and reported higher IGF-I and faster growth velocity than before treatment. There was no control group, and no adult-height outcome was reported. Hexarelin did not proceed to approval for this use.
- [4] IGF-I and growth velocity rose from baseline in 8 short prepubertal children in an uncontrolled study
Registered-study counts: ClinicalTrials.gov intervention search “hexarelin”, fetched 2026-10-10. Registered studies include trials of other uses; the gap between registered and reported is itself a finding.
03Safety signals
- Acute rise in prolactin and cortisol [2]
Intravenous hexarelin raised serum prolactin and cortisol in a dose-dependent manner in healthy adult men. - Change in pituitary-adrenal response with repeated use [5]
After 16 weeks of twice-daily subcutaneous hexarelin in adults the cortisol response to an injection was reduced, returning to baseline 4 weeks after stopping.
04What is unknown
- No randomised trial of muscle mass, strength or body composition was identified; the one uncontrolled adult study found no significant change
- Human exposure beyond about 8 months was not identified; long-term effects of repeated prolactin and cortisol rises are unstudied
- Cardiovascular effects in humans are described only in short studies; effects of long-term use on the heart are unknown
- Australian status was not verified from the TGA register; hexarelin is named in Schedule 4 and Appendix D of the Poisons Standard (October 2026, F2026L01327), which controls supply but is not a product approval
- Status in the UK, Japan and China was not verified from regulator sources for this record
05Product quality
No independent purity results have been published for this compound yet. The purity programme will publish full methods and vendor-named results, passes and failures, once its protocol has had legal review.
06Citations
- Growth hormone-releasing activity of hexarelin, a new synthetic hexapeptide, after intravenous, subcutaneous, intranasal, and oral administration in man. (1994). doi:10.1210/jcem.78.3.8126144
- Hexarelin-induced growth hormone, cortisol, and prolactin release: a dose-response study. (1996). doi:10.1210/jcem.81.12.8954038
- Growth Hormone Status during Long-Term Hexarelin Therapy (1998). doi:10.1210/jcem.83.5.4812
- Intranasal administration of the GHRP hexarelin accelerates growth in short children (1995). doi:10.1111/j.1365-2265.1995.tb02929.x
- The effect of chronic hexarelin administration on the pituitary–adrenal axis and prolactin. doi:10.1046/j.1365-2265.1999.00609.x
Every DOI is resolved against Crossref and every NCT number against ClinicalTrials.gov, title for title, before publication. Regulatory sources are cited inline above with a verbatim quote and retrieval date.
07Mechanism
Hexarelin is an agonist of the growth hormone secretagogue receptor (the ghrelin receptor); in human studies it acutely increased growth hormone, prolactin, ACTH and cortisol secretion.
Mechanism is placed last on purpose: a plausible mechanism is not evidence that a compound works in people.
Reviewed by OSMF research team (AI-assisted, source-verified) on 2026-10-10. Found an error? It goes in the corrections log: report it.