Ipamorelin

Not FDA-approved Evidence grade B — human randomised trials, not approved for that use Updated 2026-10-20

This page describes published research and public regulatory records. It is not medical advice. SoluneFit does not sell, supply, or recommend any compound. The SoluneFit app includes a private, on-device tracker for people who want a record of what they and their clinician have already decided — the app neither suggests compounds nor doses.

Also known as: Aib-His-D-2-Nal-D-Phe-Lys-NH2.

Regulatory status

Not approved. Not on the 503A bulk-substances list; its 503A nomination (category 2) was withdrawn, and it has been in 503B category 2 (significant safety risks) since 29 Sep 2023 — FDA cites immunogenicity concerns and serious adverse events including a death when given IV for gastric motility [4]. FDA warning letters in Aug 2026 treated ipamorelin products sold 'for research use only' as unapproved new drugs [5].

What it is

Growth hormone secretagogue / ghrelin-receptor (GHS-R1a) agonist; synthetic pentapeptide.

A five-amino-acid ghrelin-receptor agonist developed by Novo Nordisk that releases growth hormone. In animals it was more selective than older GHRPs, not raising ACTH or cortisol. A human trial for post-surgical bowel paralysis found no benefit, and it was never approved.

What the published research shows

Human IV PK/PD study (5 dose levels × 8 healthy men) and one phase 2 RCT in 114 bowel-surgery patients that missed its endpoint; selectivity data are from rats and pigs.

Published human studies and reports (these describe trial populations, not SoluneFit claims):

PK/PD in healthy men (Gobburu 1999): 15-minute infusions of 4.21, 14.02, 42.13, 84.27 or 140.45 nmol/kg, 8 men per dose; every dose produced a single GH pulse.
Postoperative ileus after bowel resection (Beck 2014, phase 2 RCT): 0.03 mg/kg IV twice daily from postoperative day 1 to day 7 or discharge, vs placebo, 114 patients. Median time to first tolerated meal 25.3 h vs 32.6 h (p = 0.15, not significant).
Animal pharmacology (Raun 1998): GH release in rats (ED50 80 nmol/kg IV) and conscious swine (ED50 2.3 nmol/kg) comparable to GHRP-6; no ACTH or cortisol rise at more than 200 times the GH ED50.

Mechanism, as reported

Activates the ghrelin (GH secretagogue) receptor on the pituitary and hypothalamus, producing a single short pulse of GH. In pigs it did not raise ACTH, cortisol or prolactin even at doses far above those that release GH.

Practical record

Elimination half-life: 2.0 h (confidence: medium). Terminal half-life 2 h after 15-minute IV infusions in healthy men (Gobburu 1999, n=40); clearance 0.078 L/h/kg, Vss 0.22 L/kg; GH peaked at 0.67 h. SC half-life not published. Raun 1998 is animal-only, so the human figure rests on this one study.
Studied routes: intravenous, subcutaneous.
Typical supply: Sold as lyophilised powder vials, often blended with GHRH analogues, on the research-chemical market (no approved product).

Safety signals on record

Reported adverse events: In the 114-patient surgical trial, adverse events were no more frequent than with placebo (87.5 % vs 94.8 %). FDA reports serious adverse events including a death in an IV gastric-motility study.
Contraindications: None established (no label).
Interactions: None documented.
Notes: WADA Prohibited List 2026 (in force 1 Jan 2026), S2.2.4 names ipamorelin among 'growth hormone secretagogues (GHS) and their mimetics', prohibited at all times (in and out of competition), non-specified. Its selectivity for GH over cortisol was shown in animals, not confirmed in long-term human use.

Sources

General wellness education, not medical advice. Unapproved compounds have no established dosing, purity standard, or safety profile.

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