GHRP / SubQ / 100-300mcg 2-3x daily
Ipamorelin
Ipamorelin came out of a 1990s Novo Nordisk chemistry program that removed the central dipeptide from an older growth hormone releasing peptide, and it was published in 1998 as the first GHRP-receptor agonist that released growth hormone without dragging ACTH and cortisol up with it. It reached two completed phase 2 trials, both for a gut indication rather than a growth indication: the smaller one missed its endpoint, the larger one has never reported a result, and every human use since has run outside an approved program.
In plain words
Ipamorelin is a small lab-made peptide that tells the pituitary gland to release a pulse of growth hormone. People inject it hoping for better sleep, recovery and body composition, and community reports center on sleep and recovery rather than on measured change in the body. The published evidence is thin: the only randomized trial with published results, in patients recovering from bowel surgery, did not beat placebo, and a second, larger trial finished in 2014 and has never reported anything. Its reputation as the clean one, meaning a growth hormone releaser that does not also push up stress hormones, rests on a single 1998 experiment in pigs and has never been checked in people. Ipamorelin has never been approved anywhere for anything, it is sold outside approved channels, and in 2023 the FDA placed it in its significant-safety-risk category for compounding by licensed drug-making facilities, citing impurity and immune-reaction risks.
At a glance
| Half-life | 0.083 days |
|---|---|
| Tmax | 0.028 days |
| Route(s) | SubQ |
| Published dosing range | 100-300mcg 2-3x daily |
| Vial strengths | 5, 2, 10 mg |
Reference data from the DosePlot canon -- not a protocol recommendation.
Serum curve
Single 200 mcg dose by SubQ, rendered from the same engine that powers the interactive chart. Relative levels, not lab values.
What does the evidence show?
Two things are labeled separately here because they answer different questions. The tier is how a study was built. The distance chips are whether that study touched this molecule, by this route, in a population resembling the reader. A randomized trial of a different molecule keeps its tier and still says nothing about this compound.
| Finding | Tier | Distance from use | Study |
|---|---|---|---|
| Ipamorelin failed the only randomized controlled trial of it whose results have been published. That phase 2 study enrolled 117 bowel-resection patients, of whom 114 made up the safety and modified intent-to-treat populations. At 0.03 mg/kg intravenously twice daily for up to seven days it did not significantly shorten the time to a first tolerated solid meal: median 25.3 hours on drug against 32.6 hours on placebo, p = 0.15. Treatment-emergent adverse events were reported in 87.5 percent of the ipamorelin group and 94.8 percent of the placebo group, and the authors described the regimen as well tolerated. A second and larger randomized, quadruple-masked phase 2 trial in the same indication, 320 patients across three ipamorelin dose levels and placebo, was completed in May 2014 by the same sponsor. Its results have never been posted or published. | rct | not recorded | Beck DE, Sweeney WB, McCarter MD, Ipamorelin 201 Study Group. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients.International Journal of Colorectal Disease 29(12):1527-1534, 2014 |
| A single 15-minute intravenous infusion in healthy men produces one discrete growth hormone pulse, peaking at about 0.67 hours and decaying to negligible levels. The peptide itself has a terminal half-life near 2 hours, and its kinetics were dose-proportional across a 33-fold dose range. | clinical | not recorded | Gobburu JV, Agerso H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.Pharmaceutical Research 16(9):1412-1416, 1999 |
| In conscious swine, ipamorelin released growth hormone about as well as GHRP-6 (ED50 2.3 against 3.9 nmol/kg; peak plasma GH 65 against 74 ng/ml) while producing no rise in ACTH or cortisol beyond what GHRH itself produced, tested to more than 200 times its own GH ED50. GHRP-6 and GHRP-2 raised both hormones. This single experiment is the origin of the selective label. | preclinical | not recorded | Raun K, Hansen BS, Johansen NL, Thogersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue.European Journal of Endocrinology 139(5):552-561, 1998 |
| The prolactin half of the selective description does not come from that experiment. In the same swine work, prolactin, TSH, LH and FSH were unchanged by ipamorelin and by GHRP-6 and GHRP-2 alike, so no prolactin difference between the three peptides was observed there. | preclinical | not recorded | Raun K, Hansen BS, Johansen NL, Thogersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue.European Journal of Endocrinology 139(5):552-561, 1998 |
| In healthy adults, the older peptides GHRP-2 and hexarelin do raise prolactin, ACTH and cortisol at 1 and 2 mcg/kg intravenously. The prolactin rise is smaller than TRH produces; the ACTH and cortisol rise is comparable to hCRH. | clinical | not recorded | Arvat E, di Vito L, Maccagno B, Broglio F, Boghen MF, Deghenghi R, Camanni F, Ghigo E. Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Comparison with the effects of GHRH, TRH and hCRH.Peptides 18(6):885-891, 1997 |
| A growth hormone releasing peptide and GHRH given together release more growth hormone in normal men than either does alone, which is the mechanism behind pairing a GHRP with a GHRH analogue. The synergy was demonstrated with GHRP-6; the ipamorelin pairing has never been tested this way in a published human study. | clinical | not recorded | Bowers CY, Reynolds GA, Durham D, Barrera CM, Pezzoli SS, Thorner MO. Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone.Journal of Clinical Endocrinology and Metabolism 70(4):975-982, 1990 |
| In adult rats given methylprednisolone for three months, ipamorelin at 100 mcg/kg subcutaneously three times daily raised the periosteal bone formation rate about four-fold against the steroid-only group and significantly increased calf-muscle tetanic tension. The rat dose per kilogram is far above anything used in people. | preclinical | not recorded | Andersen NB, Malmlof K, Johansen PB, Andreassen TT, Ortoft G, Oxlund H. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats.Growth Hormone and IGF Research 11(5):266-272, 2001 |
| Community protocols cluster at 100 to 300 mcg subcutaneously, two to three times a day, most often at night on an empty stomach and paired with CJC-1295 without DAC. Reported effects center on sleep depth and recovery rather than measured change in body composition. | anecdotal | not recorded | community reports aggregated from reddit, MESO-Rx, and similar forumsno study |
How did it get here?
- preclinical1981-1984
- Bowers and colleagues work outward from methionine-enkephalin analogues that weakly release growth hormone from rat pituitary tissue, running rounds of design and testing that reach a series of far more active peptides by 1981. In 1984 the same group describes GHRP-6, a hexapeptide that releases growth hormone without moving LH, FSH, TSH or prolactin. Ipamorelin arrives out of this family much later, and not from GHRP-6 itself: its series comes from the heptapeptide GHRP-1.
- preclinical1998
- Novo Nordisk publishes ipamorelin (internal code NNC 26-0161), a pentapeptide found among compounds built without the Ala-Trp pair that sits at the middle of GHRP-1. In swine it matches GHRP-6 for growth hormone release with no ACTH or cortisol rise beyond what GHRH itself produced, and the paper's own title calls it the first selective GH secretagogue.
- first-human1999-2014
- Phase 1 dose escalation in 1999: 40 healthy men, eight per dose level, by 15-minute intravenous infusion. One growth hormone pulse per dose, peak near 40 minutes, terminal half-life about 2 hours. This remains the only published human pharmacokinetic study of the compound. Development then turns to postoperative ileus, a gut-motility indication rather than a growth one, on the strength of rodent work showing faster return of bowel movement after surgery. Two randomized, placebo-controlled phase 2 trials run under the same sponsor. The first enrolls 117 patients between 2008 and 2009, is published in 2014, and misses its primary endpoint. The second is larger, a four-arm dose-finding study of 320 patients that runs from 2011 to May 2014 and closes with no results posted and no publication. Development stops there. Ipamorelin has never been approved anywhere, for anything.
- grey-market2010-2026
- With no approved product, supply moves through research-chemical vendors and later through telehealth and compounding channels, where the standard forum protocol pairs it with CJC-1295 without DAC. On September 29, 2023 the FDA placed ipamorelin acetate in category 2, the significant-safety-risk category, for section 503B outsourcing-facility compounding, citing immunogenicity risk from aggregation and peptide-related impurities, the unnatural amino acids in the sequence, and a published study reporting serious adverse events including death when ipamorelin was given intravenously to improve gastric motility. On October 29, 2024 the agency's Pharmacy Compounding Advisory Committee took up ipamorelin acetate and ipamorelin free base for the section 503A bulk drug substances list, the list that would let a pharmacy compound it for a patient, reviewing them for growth hormone deficiency and postoperative ileus. Ipamorelin does not appear on that list as codified at 21 CFR 216.23.
How is it made?
Ipamorelin is a five-residue peptide, and it is made the way short peptides are made: one amino acid at a time, on a solid support.
1. Assembling the chain. The final residue is anchored to a resin bead chosen so the peptide releases with an amide cap rather than a free acid; the molecule ends in -NH2, and that ending is part of what keeps it stable. Protected amino acids are coupled on in order. Three of the five are not ordinary amino acids at all: Aib, D-2-Nal and D-Phe are bought in as protected building blocks, and those unusual residues are much of what stops peptidases from clearing the peptide in minutes.
2. Cleaving and purifying. Strong acid releases the peptide from the resin and strips the side-chain protecting groups in one step. What comes off is a mixture: full-length peptide alongside deletion sequences that lost a residue somewhere in the assembly. Preparative reversed-phase chromatography separates them. The purified peptide is isolated as a salt, usually the acetate, which is why labels read ipamorelin acetate.
3. Filling the vial. The peptide is dissolved in water with a bulking agent such as mannitol, sterile-filtered, filled, freeze-dried, and sealed under vacuum. Identity is checked by mass spectrometry, purity by chromatography. A purity figure describes the powder and nothing more. Sterility, endotoxin load, residual solvent and counter-ion content are separate tests, and outside regulated manufacturing those are the ones that get skipped.
Worth knowing
Ipamorelin is Aib-His-D-2-Nal-D-Phe-Lys-NH2, a pentapeptide identified within a series of compounds built without the central Ala-Trp dipeptide of GHRP-1. Three of its five positions are not ordinary amino acids: Aib, D-2-Nal and D-Phe. The short chain matched the older hexapeptide GHRP-6 for growth hormone release in rat pituitary cells, in rats and in conscious swine.
Raun K, Hansen BS, Johansen NL, Thogersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue.European Journal of Endocrinology 139(5):552-561, 1998
In rats, ipamorelin cleared from plasma about five times more slowly than GHRP-6 and left mainly in the urine, while GHRP-6 left mainly in the bile. The same work measured a nasal route: roughly 20 percent of an intranasal dose of ipamorelin reached the circulation, against roughly 50 percent for GHRP-2.
Johansen PB, Hansen KT, Andersen JV, Johansen NL. Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.Xenobiotica 28(11):1083-1092, 1998
The human numbers quoted for ipamorelin, including the roughly 40-minute time to peak growth hormone and the 2-hour half-life, come from a 15-minute intravenous infusion in 40 healthy men. No subcutaneous human pharmacokinetic study of ipamorelin has been published, and subcutaneous injection is the route it is actually used by.
Gobburu JV, Agerso H, Jusko WJ, Ynddal L. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.Pharmaceutical Research 16(9):1412-1416, 1999
Reconstitution
Ipamorelin ships lyophilized and is mixed before use; the published vial strengths are 5, 2, 10 mg. The water volume you add sets the concentration, not the dose -- the calculator turns a vial size and a water volume into mg/mL, draw volume, and units on an insulin syringe.
Open in the reconstitution calculatorWritten and reviewed by Evan Marlow, developer of DosePlot · Updated 2026-08-27
Not medical advice. DosePlot is an informational tool, not a healthcare provider, and using it creates no provider-patient relationship. Do not start, stop, or change any protocol without the approval of a licensed healthcare professional.
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