Ipamorelin

Ipamorelin is the clean pulse in this catalog's growth-hormone lineup. It works through a different switch than the GHRH peptides, mimicking ghrelin to trigger a sharp burst of growth hormone, without the hunger, the cortisol jump, or the prolactin swing that older ghrelin mimetics like GHRP-6 carried. Most people don't run it alone; they add it to CJC-1295 or sermorelin for a stronger combined pulse, since the two work through separate receptors. It's dosed in small shots, one to three times a day.

Growth Hormone · Sleep · Recovery

What it does

A cleaner ghrelin pulse

Older ghrelin-mimic peptides like GHRP-6 came with a catch: they spiked cortisol and prolactin along with growth hormone, and left people ravenous. Ipamorelin hits the same ghrelin switch on the pituitary without any of that, even at doses far higher than what's needed for the growth-hormone effect. That selectivity is why it replaced the older compounds as the default choice. It comes from animal research; nobody has run the comparison directly in humans.

Sources: Raun K, Hansen, 1998

Built for stacking

Most people building a growth-hormone stack don't run ipamorelin by itself; they pair it with a GHRH peptide, CJC-1295 or sermorelin, because the two work through separate receptors on the pituitary and the combination produces a bigger pulse than either one alone. That receptor complementarity is well established at the class level, where adding a ghrelin mimetic to a GHRH peptide roughly tripled growth-hormone output in the studies behind it. The exact ipamorelin pairing itself has never been run as its own trial.

Sources: Sinha et al.

Sleep, recovery, body composition

This is how people actually run it: small shots, 100 to 300 mcg, once to three times a day, chasing better sleep, faster recovery, and steadier body composition alongside a GHRH partner. It's a light injection with a short pulse, easy to fit around a workout or bedtime. The human evidence stops at a single-dose pharmacokinetic study; the daily, injected pattern that people actually use runs on anecdote rather than a matching trial.

Sources: Gobburu JV, Agerso, 1999, peptidedosages.com, "Ipamorelin Peptide

Dosing

Community reportedCommunity subcutaneous dosing100-300 mcg, 1-3x daily

Community subcutaneous dosing
Timeframe	Dosage	Frequency	Note
Ongoing	100-300 mcg	1-3x daily	Unsourced¹

No subcutaneous human dosing study for ipamorelin was located; drawn only from vendor and protocol pages, not any peer-reviewed clinical study.

Primary structure

H*AibHHis*D-2NalFD-PheKLysNH2

5 residues · 711.9 g/mol

Full research

Evidence tier

Early human data only

The only human data demonstrating ipamorelin's GH-releasing pharmacodynamic effect is a single-dose intravenous PK/PD study in healthy volunteers; a separate Phase 2 RCT exists in humans but tested an unrelated indication (postoperative bowel motility) by an unrelated route (intravenous) and failed its primary endpoint, so neither trial supports the community's typical chronic, subcutaneous, GH-augmentation use case, which remains entirely anecdotal.

Original dosing schedule

The Dosing table above this section now shows a community- or vendor-sourced schedule (peptidedosages.com). The regulatory-label or clinical-trial dosing this entry was originally built on is kept here, unchanged, rather than removed.

Clinical trial

PK/PD study, healthy volunteers, IV (Gobburu et al. 1999)
Timeframe	Dosage	Frequency	Note
Single dose	3-100 mcg/kg	IV infusion over 15 min	Dose-escalation design¹

Approximately 3, 10, 30, 60, and 100 mcg/kg tested, eight healthy male subjects per dose level.

Clinical trial

Postoperative ileus trial, IV (Beck et al. 2014)
Timeframe	Dosage	Frequency	Note
Days 1-7	30 mcg/kg	twice daily	Postoperative, until discharge

Identity

Full name	Ipamorelin (developmental code NNC 26-0161)
Class	Selective ghrelin-receptor (GHS-R1a) agonist, synthetic pentapeptide
Molecular weight	711.9 g/mol
Sequence	H-Aib-His-D-2Nal-D-Phe-Lys-NH2

Mechanism of action

Plain language

This is not a copy of the brain's GHRH signal at all. It mimics a different hormone, ghrelin (the "hunger hormone"), which also triggers a burst of growth hormone release through its own separate switch on the pituitary.

Technical

Selective ghrelin-receptor (growth hormone secretagogue receptor, GHS-R1a) agonist, mechanistically and structurally distinct from the GHRH analogs in this category (sermorelin, both CJC-1295 forms, tesamorelin). Binds the same receptor as endogenous ghrelin, triggering GH release through signaling independent of the GHRH receptor. A key distinguishing pharmacologic feature versus older ghrelin mimetics (GHRP-6, GHRP-2): ipamorelin does not meaningfully raise ACTH, cortisol, prolactin, FSH, LH, or TSH, even at doses roughly 200-fold above its GH-releasing ED50, in rat and pig models. It produces a single, sharp GH pulse rather than sustained elevation. It is commonly stacked with a GHRH analog (sermorelin or either CJC-1295 form) for the same receptor-complementarity reason: GHRH-receptor agonism plus ghrelin-receptor agonism converges on the somatotroph and produces a larger pulsatile GH release than either pathway alone, a synergy documented at the class level using GHRH plus GHRP-2 (54-fold increase in pulsatile GH secretion versus 47-fold for GHRP-2 alone and 20-fold for GHRH alone).

Sources: Raun K, Hansen, 1998, Sinha et al.

What it’s used for

Human trials, not approved for this use

GH-release pharmacology was demonstrated directly in healthy human volunteers via a single-dose intravenous, dose-ranging pharmacokinetic-pharmacodynamic study.
Sources: Gobburu JV, Agerso, 1999
A Phase 2, multicenter, double-blind, placebo-controlled RCT tested intravenous ipamorelin for postoperative ileus after bowel resection surgery; it did not meet its primary efficacy endpoint. This is a different indication (GI motility, not GH augmentation) and a different route (intravenous, not the subcutaneous route used in community protocols).
Sources: Beck DE, et al., 2014

Off-label / community use

All anabolic, anti-aging, body-composition, sleep, or recovery uses, which is how this compound is actually marketed and used, rest on anecdote only; no controlled human data for that use case were located.
Sources: peptidedosages.com, "Ipamorelin Peptide

Pharmacokinetics

Terminal half-life	Clinical trial Approximately 2 hours (intravenous) Sources: Gobburu JV, Agerso, 1999
Clearance	Clinical trial 0.078 L/h/kg Sources: Gobburu JV, Agerso, 1999
Volume of distribution at steady state	Clinical trial 0.22 L/kg Sources: Gobburu JV, Agerso, 1999
GH peak (Tmax)	Clinical trial Approximately 0.67 hours (about 40 minutes) after intravenous dosing, with an exponential decline to near-negligible GH concentration at all tested doses Sources: Gobburu JV, Agerso, 1999
Subcutaneous route pharmacokinetics	Not established No citable figure. No dedicated human pharmacokinetic study for the subcutaneous route, the route used in community practice, was located. Secondary and vendor sources describe subcutaneous dosing as producing peak GH at 30-45 minutes with return to baseline within 2-3 hours, but the underlying human SC-route PK study supporting that specific claim was not identified; treat that figure cautiously as secondary-sourced only.

Reconstitution

Vial strength	2 mg or 5 mg lyophilized vial (commercial)
Diluent	Bacteriostatic water
Diluent volume	2 mL (5 mg vial, worked example)
Concentration	2.5 mg/mL (2500 mcg/mL) for a 5 mg vial reconstituted with 2 mL

Sources: Commercial vendor pages

Storage and post-reconstitution stability

Unopened storage

Lyophilized peptide represented by vendors as refrigerated or frozen and light-protected before reconstitution; not independently validated by any regulatory source.

Post-reconstitution stability – Vendor claim

Approximately 20 to 30 days. Refrigerated

Sources: Commercial vendor pages

No citable figure. Not independently validated by any regulatory source; no FDA-approved ipamorelin product exists.

Safety

Notable risks

In animal and in-vitro pharmacology, ipamorelin did not raise cortisol, ACTH, or prolactin even at doses roughly 200-fold above its GH-releasing dose.
Sources: Raun K, Hansen, 1998
In the human postoperative ileus RCT, ipamorelin was reported as well tolerated with an acceptable safety profile in that surgical population, though it did not demonstrate efficacy for its tested indication.
Sources: Beck DE, et al., 2014
No human data address chronic, multi-week or multi-month, dosing safety, long-term IGF-1 trajectory, glucose tolerance, or malignancy risk for this compound; long-term human safety data for ipamorelin are essentially absent from the published literature. No oncologic events were observed in the trials that were run, but no ipamorelin study has tested cancer risk as an endpoint. Contraindications and monitoring recommendations have not been established in any regulatory label, because the drug is not approved anywhere.

Sources

Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998. (1998)
Gobburu JV, Agerso H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999. (1999)
Beck DE, et al. Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients. Int J Colorectal Dis. 2014. (2014)
Sinha et al. Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. Translational Andrology and Urology.
peptidedosages.com, "Ipamorelin Peptide: Benefits, Dosage, Safety" (commercial vendor)
Commercial vendor pages, cited for vial strengths and reconstitution/storage convention; no individual URL was named in the source research document for this specific figure

This is a research and educational reference, not medical advice. Nothing on this site is a recommendation to use any compound.