Which has stronger evidence, Ipamorelin or Hexarelin?

Ipamorelin has stronger published evidence than Hexarelin: tier A (Controlled human trials) vs tier B (Small human studies). Ipamorelin: Randomized, placebo-controlled phase 2 trials in postoperative ileus were completed (no benefit shown); not approved. Hexarelin: Human data are limited to small pharmacological studies; no approved use. Tiers rate the strength of published evidence, not effectiveness.

Is Ipamorelin FDA-approved?

Ipamorelin is not FDA-approved.

How do Ipamorelin and Hexarelin work?

Ipamorelin is a pentapeptide ghrelin receptor (GHS-R1a) agonist that stimulates growth hormone release from the anterior pituitary in a dose-dependent manner. Hexarelin is a synthetic hexapeptide and the most potent GHS-R1a agonist, producing the largest acute GH pulse among all GHRPs.

Comparison · Updated 2026-11-08

Ipamorelin VS Hexarelin

Short answer

Ipamorelin has stronger published evidence than Hexarelin: tier A (Controlled human trials) vs tier B (Small human studies).

Neither Ipamorelin nor Hexarelin is FDA-approved.

Both are prohibited in sport by WADA under section S2.

Ipamorelin Hexarelin Open in matchups

Side by side

Field	Ipamorelin PubChem CID 9831659	Hexarelin PubChem CID 6918297
Evidence tier	A Tier A · Controlled human trials	B Tier B · Small human studies
Tier rationale	Randomized, placebo-controlled phase 2 trials in postoperative ileus were completed (no benefit shown); not approved.	Human data are limited to small pharmacological studies; no approved use.
FDA status	Not approved	Not approved
Other approvals	None listed	None listed
WADA	Prohibited · S2Peptide hormones, growth factors, related substances and mimetics	Prohibited · S2Peptide hormones, growth factors, related substances and mimetics
Family	GH & Growth	GH & Growth
Residues	Not on file	Not on file
Molecular weight	Not on file	Not on file
Formula	Not on file	Not on file
Discovered	1998Described by Novo Nordisk as a selective GH secretagogue.	Not on file
Routes studied	Subcutaneous, Intramuscular	Subcutaneous, Intramuscular
Mechanism	Ipamorelin is a pentapeptide ghrelin receptor (GHS-R1a) agonist that stimulates growth hormone release from the anterior pituitary in a dose-dependent manner. Unlike other GHRPs, it has high selectivity for GH release without significantly elevating ACTH, cortisol, or prolactin, making it the cleanest GHRP available.	Hexarelin is a synthetic hexapeptide and the most potent GHS-R1a agonist, producing the largest acute GH pulse among all GHRPs. It acts through both pituitary and hypothalamic pathways to amplify GH release.
Safety notes	Well-tolerated in Phase II clinical trials.	Human trial data available.
Cited studies	0 studies	0 studies

Questions

Which has stronger evidence, Ipamorelin or Hexarelin?: Ipamorelin has stronger published evidence than Hexarelin: tier A (Controlled human trials) vs tier B (Small human studies). Ipamorelin: Randomized, placebo-controlled phase 2 trials in postoperative ileus were completed (no benefit shown); not approved. Hexarelin: Human data are limited to small pharmacological studies; no approved use. Tiers rate the strength of published evidence, not effectiveness.
Is Ipamorelin FDA-approved?: Ipamorelin is not FDA-approved.
Is Hexarelin FDA-approved?: Hexarelin is not FDA-approved.
Are Ipamorelin and Hexarelin banned in sport?: Both are prohibited in sport by WADA under section S2.
How do Ipamorelin and Hexarelin work?: Ipamorelin is a pentapeptide ghrelin receptor (GHS-R1a) agonist that stimulates growth hormone release from the anterior pituitary in a dose-dependent manner. Hexarelin is a synthetic hexapeptide and the most potent GHS-R1a agonist, producing the largest acute GH pulse among all GHRPs.