Ipamorelin: dosing in studies, side effects, half-life and how it works
What 63 indexed publications and 2 randomized trials actually state about ipamorelin, sentence by sentence, each tied to its source and labeled by the kind of evidence it is.
At a glance
What it is and how it acts
Ipamorelin is a peptide in the ghrelin mimetics class (ghrelin receptor, or GHS-R1a, agonist) studied in human and preclinical research. Europe PMC indexes 63 publications naming Ipamorelin or a listed alias in a title or abstract as of . The current ledger contains 2 human clinical studies, both randomized, alongside animal, analytical, and in-vitro records.
That publication count is a discovery measure, not proof of efficacy or safety. The cited human evidence is limited and mixed: one postoperative-ileus trial reported no significant difference from placebo in its key efficacy analyses. This page reports what the studies state, sentence by sentence, with each statement tied to its source and labeled by evidence type.
It does not recommend use or translate study doses into personal instructions.
What the evidence level means
Publication counts show what is indexed, not how strong the evidence is. The ledger below separates human clinical records from preclinical, analytical, and in-vitro work.
Human-study result: The 2014 randomized postoperative-ileus study reported no significant differences between ipamorelin and placebo in its key and secondary efficacy analyses. The 1999 randomized study examined growth-hormone release and pharmacokinetics, not an approved therapeutic indication.
Interpretation boundary: An indexed publication count is a discovery measure. It does not establish efficacy, safety, approval, or a personal treatment plan.
Ipamorelin in two minutes
What it is. A synthetic five-amino-acid peptide that makes the pituitary release a short pulse of growth hormone by acting on the ghrelin receptor. Developed by Novo Nordisk in the 1990s; taken into a phase 2 trial for post-surgical gut recovery, where it did not beat placebo; never approved anywhere.
What the research actually shows. Two human trials exist (quoted below). One measured how the body handles it in healthy volunteers: a two-hour half-life and a growth hormone peak about 40 minutes after dosing. The other, in 114 surgical patients, found no benefit. No trial has measured muscle, fat, sleep, recovery or ageing outcomes in people. Animal and cell work shows growth hormone release with little effect on cortisol or prolactin, which is the basis of its reputation for selectivity.
What people commonly report using. 100 to 300 micrograms by subcutaneous injection, one to three times daily, usually paired with CJC-1295, often at night. Those figures come from communities and clinics, not trials.
Status. Not FDA-approved; on FDA's compounding watch list with safety concerns flagged; prohibited in sport at all times under WADA's S2 category (see regulatory status).
Where the evidence is thinnest. Long-term safety, effects on blood sugar and IGF-1 with repeated use, interactions, and any human outcome anyone is actually buying it for.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
How ipamorelin works
Written from general pharmacology and the development record, and marked as editorial synthesis; the measurements behind it are quoted in the biomarker section.
- Editorial synthesis from general knowledge
- Editorial synthesis from general knowledge
- Editorial synthesis from general knowledge
What happened in the human studies?
This record's ledger holds 2 primary human studies, of which 2 are trials. Few enough to show in full: each card quotes what its abstract reported about Ipamorelin. Read them before any other section on this page.
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There were no significant differences between ipamorelin and placebo in the key and secondary efficacy analyses.
Sourcepmid-25331030· quoted verbatim from the abstract -
Ipamorelin induces the release of GH at all dose levels with the concentration (SC50) required for half-maximal GH stimulation of 214 nmol/L and a maximal GH production rate of 694 mIU/L/h.
Sourcepmid-10496658· quoted verbatim from the abstract
What did the studies find?
Reported outcomes, not benefits. Two human trials exist, and neither measured the body-composition, sleep or recovery outcomes ipamorelin is marketed for. One row per primary study in this record's ledger. Fields are read from each paper's indexing and abstract. "Analytical method" marks papers about detecting or measuring the compound rather than about its effects.
| Study | Design | n | Species | Dose | Route | Duration | Reported outcome | Tier |
|---|---|---|---|---|---|---|---|---|
| Beck 2014 | Randomized controlled trial | 114 | Humans | — | intravenous | — | There were no significant differences between ipamorelin and placebo in the key and secondary efficacy analyses. | Human clinical trial |
| Gobburu 1999 | Randomized controlled trial | — | Humans | — | — | — | Ipamorelin induces the release of GH at all dose levels with the concentration (SC50) required for half-maximal GH stimulation of 214 nmol/L and a maximal GH production rate of 694 mIU/L/h. | Human clinical trial |
| Thomas 2011 | Analytical method | — | Humans | — | — | — | — | Observational, human |
| Tewari 2026 | Animal study | — | Rats | — | — | — | — | Animal, preclinical |
| Z 2024 | Animal study | — | — | 1-3 mg/kg | intraperitoneal | — | Anamorelin and ipamorelin inhibited EFS-induced contractions of isolated ileum by 94.4 % (half-maximal inhibitory concentration [IC 50 ]=14.0 µM) and 54.4 % (IC 50 =11.7 µM), respectively. | Animal, preclinical |
| Gouda 2024 | Animal study | — | — | — | — | 21 days | — | Animal, preclinical |
| Mohammadi 2020 | Animal study | — | Rats | — | intravenous, oral | — | Compared to vehicle controls, ghrelin mimetics HM01 and ipamorelin significantly attenuated colonic hypersensitivity and somatic allodynia. | Animal, preclinical |
| Timms 2014 | Analytical method | — | Rats | — | — | — | — | Animal, preclinical |
| Kwok 2013 | Analytical method | — | — | — | — | — | — | Animal, preclinical |
| Thomas 2012 | Animal study | — | Rats | — | — | — | — | Animal, preclinical |
| Greenwood-Van Meerveld 2012 | Animal study | — | Rats | — | intragastric, intravenous | — | In a separate group of rats subjected to laparotomy and intestinal manipulation, the gastric fundus was isolated and tissue segments were suspended in an organ bath to assess the effect of ipamorelin (1 µM) on gastric… | Animal, preclinical |
| Venkova 2009 | Animal study | — | Rats | 0.01-1 mg/kg; 1 mg/kg | intravenous | 2 day | Compared with the vehicle, a single dose of ipamorelin (1 mg/kg) or GHRP-6 (20 microg/kg) decreased the time to the first bowel movement but had no effect on cumulative fecal output, food intake, or body weight gain… | Animal, preclinical |
| Aagaard 2009 | Animal study | — | Rats | 0.5 mg | — | — | Compared to pair-fed controls, prednisolone increased CUNS (p Conclusion Accelerated nitrogen wasting in the liver and other organs caused by prednisolone treatment was counteracted by treatment with either GH or its… | Animal, preclinical |
| Adeghate 2004 | Animal study | — | Rats | — | — | — | Ipamorelin evoked significant (p Conclusion IPA stimulates insulin release through the calcium channel and the adrenergic receptor pathways. | Animal, preclinical |
| Johansen 2003 | Animal study | — | Rats, Mice | — | intravenous | — | — | Animal, preclinical |
| Peschke 2002 | Animal study | — | Rats, Dogs, Swine | — | — | — | — | Animal, preclinical |
| Andersen 2001 | Animal study | — | Rats | — | subcutaneous | — | — | Animal, preclinical |
| Johansen 1999 | Animal study | — | Rats | — | intravenous, subcutaneous | — | The responsiveness of the pituitary to a provocative i.v. dose of ipamorelin or GHRH showed that the plasma GH response was marginally reduced (P<0.03) after ipamorelin, but unchanged after GHRH. | Animal, preclinical |
| Johansen 1998 | Animal study | — | Rats | — | intranasal, intravenous | — | Ipamorelin differed markedly from the other peptides investigated, demonstrating a systemic plasma clearance 5-fold lower than that of GHRP-6. | Animal, preclinical |
| Worm 2018 | In vitro study | — | Humans | — | — | — | The versatility of this carborane for the development of peptidic boron delivery agents was further demonstrated by the generation of highly potent, boron-loaded conjugates using the backbone of the known ghrelin… | Mechanistic, in vitro |
| Tsivou 2017 | Analytical method | — | Humans | — | — | — | — | Mechanistic, in vitro |
| Thomas 2016 | Analytical method | — | Humans | — | — | — | — | Mechanistic, in vitro |
What doses did studies use?
These are the doses studies administered, in the species and populations they studied, not a therapeutic range. No human trial has established an ipamorelin dose for the uses it is marketed for. Each entry is a sentence quoted from the study's abstract, with the study's design, sample size and year in front of it. Comparator doses in the same sentence are not attributed to ipamorelin.
- Doses stated in the abstract: 1-3 mg/kg
In other experiments, ferrets were administered anamorelin (1-3 mg/kg), ipamorelin (1-3 mg/kg), or vehicle intraperitoneally (i.p.) 30 s before cisplatin (5 mg/kg, i.p.) and then every 24 h, and their behaviour was recorded for up to 72 h.
Sourcepmid-39043357· quoted verbatim from the abstract, emphasis added - Doses stated in the abstract: 0.01-1 mg/kg; 1 mg/kg
Ipamorelin (0.01-1 mg/kg), growth hormone-releasing peptide (GHRP)-6 (20 microg/kg), or vehicle (saline) were administered via intravenous bolus infusion after a single dosing or a 2-day repetitive dosing regimen (four doses a day at 3-h intervals).
Sourcepmid-19289567· quoted verbatim from the abstract, emphasis added - Doses stated in the abstract: 0.5 mg
Five groups of rats were included: (1) free-fed controls (2) pair-fed controls (3) prednisolone (delcortol, 4 mg x kg(-1) x day(-1)) (4) prednisolone and GH (1 mg x kg(-1) x day(-1)) (5) prednisolone and Ipamorelin (0.5 mg x kg(-1) x day(-1)).
Sourcepmid-19231263· quoted verbatim from the abstract, emphasis added
Ipamorelin dosage chart: studies versus what circulates
Two very different kinds of figure appear when people search for an ipamorelin dose. This table keeps them apart.
Everything in the first two rows was administered in a study to answer a research question; nothing in the lower rows has been tested for the purposes it is used for. Body-weight doses from animals do not convert to people by simple arithmetic (the published figures).
| Source of the figure | Dose | Frequency and duration | What it was for |
|---|---|---|---|
| Human pharmacokinetic study (1999) | Five intravenous infusion rates, 4.2 to 140 nmol/kg over 15 minutes | Single doses | Healthy volunteers; measured GH release and clearance |
| Human phase 2 trial (2014) | 0.03 mg/kg intravenously, twice daily | Up to 7 days | 114 patients after bowel surgery; no benefit over placebo |
| Animal studies | 10 to 300 µg/kg, various routes | Days to weeks | Growth hormone release, bone growth, gut motility in rats and pigs |
| Commonly reported (communities, clinics) | 100 to 300 µg subcutaneously | 1 to 3 times daily, often 8 to 12 weeks | Untested for these uses; frequently combined with CJC-1295 |
| Commonly reported timing | Fasted, before bed or after training | — | Reasoning: avoid blunting the GH pulse with a glucose rise; untested |
The most common misreading is treating the study doses as a validated human range. They were chosen to characterise the drug or to test a surgical outcome, not to optimise anything a healthy person wants. The commonly reported figures, in turn, have never been measured against any outcome, and their consistency across websites reflects copying, not evidence.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
What side effects did studies report?
Events and their frequency as each study reported them, with the denominator where the abstract gives one.
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Safety was assessed by monitoring adverse events and laboratory tests.
Sourcepmid-25331030· quoted verbatim from the abstract
Who ipamorelin is discussed for, and who is commonly advised to avoid it
There is no approved indication, so there is no approved patient. What follows is the pharmacological reasoning that appears in the literature on growth hormone secretagogues generally.
The interest. Because it raises growth hormone in a pulse rather than supplying growth hormone directly, ipamorelin is discussed by people seeking the effects associated with growth hormone, body composition, recovery, sleep quality, while avoiding the feedback suppression and cost of injected growth hormone. That reasoning is plausible and untested in any human trial.
Reasons for caution that recur in the secretagogue literature.
- Active or recent cancer. Growth hormone and IGF-1 promote cell growth; secretagogues are generally regarded as inappropriate where a growth-hormone-sensitive tumour may be present.
- Diabetes and impaired glucose tolerance. Growth hormone raises blood glucose and opposes insulin; small rises in fasting glucose and HbA1c are reported with several secretagogues, notably the oral agent ibutamoren; the site's ghrelin-mimetics class page lists the compounds this reasoning applies to.
- Pregnancy and breastfeeding. No data at all.
- Adolescents. Growth plates respond to growth hormone; the rat bone-growth study is the reason this appears on every caution list.
- Acromegaly, pituitary disease, and uncontrolled thyroid disease. The axis being stimulated is already abnormal.
- Competitive athletes subject to anti-doping rules, for whom detection methods exist and a positive test is a four-year default sanction; see how evidence is tiered here for why community reports are labelled as such.
None of these is specific to ipamorelin; they follow from what growth hormone does. Their absence from many marketing pages is a gap in those pages, not evidence of safety.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
What did studies measure: growth hormone, cortisol, ACTH
Laboratory and clinical measures the studies report tracking, including which hormones did and did not change.
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Ghrelin-receptor stimulation has promotility effects in the upper and lower gastrointestinal tract.
Sourcepmid-25331030· quoted verbatim from the abstract -
To examine the pharmacokinetics (PK) and pharmacodynamics (PD) of ipamorelin, a growth hormone (GH) releasing peptide, in healthy volunteers.
Sourcepmid-10496658· quoted verbatim from the abstract -
Neither of compounds administered i.p. had any effect on cisplatin-induced acute or delayed emesis, but both inhibited associated cisplatin-induced weight loss on the last day of delayed phase (48-72 h) by approximately 24 %.
Sourcepmid-39043357· quoted verbatim from the abstract -
The growth hormone releasing peptides (GHRPs) hexarelin, ipamorelin, alexamorelin, GHRP-1, GHRP-2, GHRP-4, GHRP-5, and GHRP-6 are all synthetic met-enkephalin analogues that include unnatural D-amino acids.
Sourcepmid-24574167· quoted verbatim from the abstract -
The most promising candidates are the growth hormone releasing peptide (GHRP)-1, -2, -4, -5, -6, hexarelin, alexamorelin, and ipamorelin.
Sourcepmid-23101768· quoted verbatim from the abstract -
Delayed gastric emptying is a common disorder with few effective therapeutic options.
Sourcepmid-27186127· quoted verbatim from the abstract
Reported timelines
Onset, peak and duration figures as each study reported them.
-
The PK parameters showed dose-proportionality, with a short terminal half-life of 2 hours, a clearance of 0.078 L/h/kg and a volume of distribution at steady-state of 0.22 L/kg.
Sourcepmid-10496658· quoted verbatim from the abstract
What happens after a dose, and what people report over weeks
Minutes and hours are measured; weeks and months are reported. The two should not be read in the same voice.
Measured. In healthy volunteers, growth hormone rose to a single peak about 40 minutes after an infusion and returned toward baseline over the following hours; the drug's own half-life was about two hours. That is one pulse per injection, which is why the compound is discussed as mimicking the body's natural pattern rather than flattening it.
Commonly reported, untested. Users describe warmth or flushing and sometimes a headache within minutes of injection, hunger within an hour, subjectively deeper sleep within the first week or two, and changes in recovery and body composition described over eight to twelve weeks. Injection-site redness and water retention are mentioned. None of this has been measured against placebo, and expectancy effects in self-report over that timescale are large.
What would change the picture. A placebo-controlled trial measuring IGF-1, body composition and sleep architecture over three months. None has been registered; the open questions section tracks this.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
Escalation schedules used in studies
How trials stepped doses, reported as study design.
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A trial was conducted with a dose escalation design comprising 5 different infusion rates (4.21, 14.02, 42.13, 84.27 and 140.45 nmol/kg over 15 minutes) with eight healthy male subjects at each dose level.
Sourcepmid-10496658· quoted verbatim from the abstract
How long did studies run?
A study's duration is how long the trial ran. It is not a recommended cycle, and no trial has tested one. Treatment and follow-up periods as stated in each abstract.
- Durations stated: 21 days
The administration of either 5 or 30 µg of IPA for 21 days led to a significant and dose-dependent rise in food intake concomitant with a significant increase in the numbers of primary spermatocytes, secondary spermatocytes, and early spermatids compared to the control group.
Sourcepmid-38996787· quoted verbatim from the abstract, emphasis added - Durations stated: 2 day
Ipamorelin (0.01-1 mg/kg), growth hormone-releasing peptide (GHRP)-6 (20 microg/kg), or vehicle (saline) were administered via intravenous bolus infusion after a single dosing or a 2-day repetitive dosing regimen (four doses a day at 3-h intervals).
Sourcepmid-19289567· quoted verbatim from the abstract
Routes studied
Routes of administration named in each study.
- administration by intravenous route reported
The intervention was intravenous infusions of 0.03-mg/kg ipamorelin vs placebo twice daily, on postoperative day 1 to 7 or hospital discharge.
Sourcepmid-25331030· quoted verbatim from the abstract - administration by intraperitoneal route reported
In other experiments, ferrets were administered anamorelin (1-3 mg/kg), ipamorelin (1-3 mg/kg), or vehicle intraperitoneally (i.p.) 30 s before cisplatin (5 mg/kg, i.p.) and then every 24 h, and their behaviour was recorded for up to 72 h.
Sourcepmid-39043357· quoted verbatim from the abstract - administration by intravenous, oral route reported
Ghrelin mimetics HM01 and ipamorelin were administered orally or intravenously, respectively.
Sourcepmid-32801950· quoted verbatim from the abstract - administration by intragastric, intravenous route reported
Following the surgery rats received ipamorelin (0.014-0.14 µmol/kg) or vehicle control via intravenous administration.
Sourcepmid-27186127· quoted verbatim from the abstract - administration by intravenous route reported
Ipamorelin (0.01-1 mg/kg), growth hormone-releasing peptide (GHRP)-6 (20 microg/kg), or vehicle (saline) were administered via intravenous bolus infusion after a single dosing or a 2-day repetitive dosing regimen (four doses a day at 3-h intervals).
Sourcepmid-19289567· quoted verbatim from the abstract - administration by intravenous route reported
The growth hormone (GH) and insulin-like growth factor I (IGF-I) axis were studied in streptozotocin (STZ) diabetic and nondiabetic female mice following intravenous (IV) injection of the GH secretagogue (GHS) ipamorelin or saline.
Sourcepmid-14630569· quoted verbatim from the abstract
Weight-normalized doses, as published
Per-kilogram figures exactly as each study published them, for the species it studied.
- Weight-normalized doses as published: 1-3 mg/kg
In other experiments, ferrets were administered anamorelin (1-3 mg/kg), ipamorelin (1-3 mg/kg), or vehicle intraperitoneally (i.p.) 30 s before cisplatin (5 mg/kg, i.p.) and then every 24 h, and their behaviour was recorded for up to 72 h.
Sourcepmid-39043357· quoted verbatim from the abstract, emphasis added - Weight-normalized doses as published: 0.01-1 mg/kg; 1 mg/kg
Ipamorelin (0.01-1 mg/kg), growth hormone-releasing peptide (GHRP)-6 (20 microg/kg), or vehicle (saline) were administered via intravenous bolus infusion after a single dosing or a 2-day repetitive dosing regimen (four doses a day at 3-h intervals).
Sourcepmid-19289567· quoted verbatim from the abstract, emphasis added
Weight-normalized figures above are reproduced exactly as each study published them, for the species it studied. Dose does not scale linearly with body mass between species: metabolic rate, clearance and receptor density differ, and regulatory guidance uses allometric, not proportional, conversion. A mg/kg figure from a rat study is a fact about that rat study and nothing else.
What is commonly reported outside the literature
What circulates in user communities and clinic marketing, reported so a reader knows the figures and their origin. None of it has been tested in a trial, and none of it is a suggestion.
- Editorial synthesis from general knowledge
- Editorial synthesis from general knowledge
Reconstituting ipamorelin: concentrations for common vial sizes
Ipamorelin is sold as a freeze-dried powder that is dissolved before use. The arithmetic below is exact; the choice of what to draw is not made here.
Concentration is mass divided by volume. Adding 2 mL of bacteriostatic water to a vial gives the concentrations in the table; the last column is the volume that would contain 100 µg, purely as a worked example of the arithmetic.
| Vial | Diluent added | Concentration | Volume holding 100 µg on a U-100 syringe |
|---|---|---|---|
| 2 mg | 2 mL | 1,000 µg/mL | 0.10 mL (10 units) |
| 5 mg | 2 mL | 2,500 µg/mL | 0.04 mL (4 units) |
| 5 mg | 2.5 mL | 2,000 µg/mL | 0.05 mL (5 units) |
| 10 mg | 2 mL | 5,000 µg/mL | 0.02 mL (2 units) |
Points people commonly get wrong: reading a 5 mg vial as 5 mL; assuming the vial's stated mass is all peptide when a certificate of analysis may show 80 to 90 percent net peptide content; and using sterile rather than bacteriostatic water for a multi-dose vial, which has no preservative against bacterial growth over the days the vial is in use. The reconstitution calculator does the division with the formula shown.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
Reconstitution mathematics
Lyophilised peptide is supplied as a mass in a vial and dissolved in a stated volume of diluent. Two figures follow from that and nothing else:
- Concentration = mass in vial ÷ diluent volume. A 5 mg vial in 2 mL is 2.5 mg/mL, or 2,500 mcg/mL.
- Volume for a given mass = that mass ÷ concentration. 250 mcg at 2,500 mcg/mL is 0.1 mL. On a U-100 insulin syringe, where 1 mL is 100 units, that is 10 units.
Study doses on this page are quoted as published, in the units the authors used. Converting between mcg, mg and IU, or between a mass and a syringe volume, is arithmetic; deciding a mass is not, and this page does not do it. The reconstitution calculator performs the conversion with the formula shown.
Reading a certificate of analysis
A certificate of analysis is a laboratory report on one batch. Reading it means checking four things in order.
- Identity. Mass spectrometry should report an observed molecular mass matching the peptide's theoretical mass within the instrument's stated tolerance. A certificate with no mass spectrometry, or one that lists only the expected value, has not confirmed identity.
- Purity. HPLC purity is the area of the main peak as a share of all peaks, at a stated wavelength. It says nothing about what the other peaks are, and it is not a measure of quantity.
- Quantity. Net peptide content, by amino acid analysis or UV, is the fraction of the vial's mass that is peptide rather than counter-ions and water. A 5 mg vial at 80% net content holds 4 mg of peptide, and every concentration figure above changes accordingly.
- Provenance. The batch number on the certificate should match the vial, the laboratory should be named and independent of the seller, and the test date should be recent.
This page rates no supplier and links to none. It describes how to read the document.
Equipment described in studies
Published human studies of injectable peptides report the same small set of materials: single-use insulin syringes with fixed needles, most often U-100 with 29 to 31 gauge needles; bacteriostatic water or sterile water for injection as diluent, with the choice stated in the methods; alcohol swabs; and refrigerated storage of reconstituted solution. Animal studies more often report intraperitoneal or intragastric administration and state the vehicle used. Where a study in this record's ledger names its materials or vehicle, that sentence appears under storage or routes above; where it does not, nothing is assumed here.
Storage and handling
As a freeze-dried powder, peptides of this size are typically kept refrigerated at 2 to 8 °C for months or frozen at −20 °C for longer, protected from light and moisture; suppliers' own stability statements vary and a certificate of analysis dated close to purchase matters more than a generic figure. Once dissolved in bacteriostatic water, a vial is commonly kept refrigerated and used within about four weeks; repeated warming, agitation and sunlight degrade peptide solutions faster than time alone. Cloudiness, colour or particles in a solution that was clear are reasons to discard it. The one published stability finding in this record's ledger concerns detection in urine for anti-doping, not shelf life.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
Blood tests and monitoring that appear in the literature
A clinician following a growth hormone secretagogue would look at the axis it stimulates and the metabolic cost of stimulating it.
| Measure | Why it appears | When it is typically drawn |
|---|---|---|
| IGF-1 | The stable downstream marker of growth hormone exposure | Baseline, then after 6 to 8 weeks |
| Fasting glucose and HbA1c | Growth hormone opposes insulin | Baseline and periodically |
| Cortisol and prolactin | The selectivity claim: ipamorelin is reported not to raise them | Baseline; the 1998 animal study is the origin of the claim |
| Thyroid panel | Growth hormone alters T4 to T3 conversion | Baseline |
| Lipids and blood pressure | Fluid retention and metabolic shifts with GH | Baseline and periodically |
No monitoring schedule has been validated for ipamorelin specifically; the table reflects what is monitored for growth hormone therapy and for other secretagogues.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
Common mistakes in how ipamorelin is discussed
- Reading the two human trials as efficacy evidence. One measured pharmacokinetics; the other failed its endpoint. Neither supports the uses it is sold for.
- Treating 'selective' as 'safe'. Selectivity means less cortisol and prolactin release than GHRP-6; it says nothing about glucose, IGF-1 or long-term effects.
- Converting animal doses by body weight. A µg/kg figure from rats is a fact about rats. Allometric scaling is not linear, and no human dose was ever derived this way in a trial.
- Assuming the vial contains what the label says. Unregulated products vary in identity, purity and net peptide content; a certificate from an independent laboratory, matched to the batch, is the only check.
- Stacking on the assumption the combination was studied. Three indexed papers mention ipamorelin and CJC-1295 together; none tested the pair for a body-composition or recovery outcome.
- Calling it legal because it is sold. Sale as a 'research chemical' is not approval, and in sport it is prohibited at all times.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
Ipamorelin vs CJC-1295, sermorelin, tesamorelin and GHRP-6
These are the comparisons people search for. Only sermorelin and tesamorelin have ever been approved medicines, and only tesamorelin still is, for one narrow indication.
| Compound | Mechanism | Half-life (reported) | Selectivity for GH | Human evidence | Status |
|---|---|---|---|---|---|
| Ipamorelin | Ghrelin receptor agonist (GHS-R1a) | ~2 h | High: little cortisol or prolactin rise | Two trials; no efficacy shown | Not approved; WADA S2 |
| CJC-1295 (modified GRF 1-29) | GHRH analogue; with DAC, days-long half-life | Minutes (no DAC) to ~6 to 8 days (DAC) | Not applicable (different receptor) | Phase 1 to 2 data; development stopped | Not approved; WADA S2 |
| Sermorelin | GHRH analogue (GHRH 1-29) | ~10 to 20 min | Not applicable | Approved for paediatric GH deficiency (US, 1997), later withdrawn commercially | Withdrawn; WADA S2 |
| Tesamorelin | GHRH analogue | ~30 min | Not applicable | Phase 3 trials; approved for HIV-associated abdominal fat | Approved (US, 2010) for one indication; WADA S2 |
| GHRP-6 | Ghrelin receptor agonist | ~20 to 30 min | Low: raises cortisol, prolactin and hunger | Early human pharmacology only | Not approved; WADA S2 |
The structural point behind every 'stack' is that a GHRH analogue and a ghrelin receptor agonist act on two different receptors that together drive the same growth hormone pulse, so combining them is pharmacologically coherent. Coherent is not the same as tested: no trial has measured any combination of these compounds for the outcomes users pursue. Head-to-head pages: ipamorelin vs GHRP-6; sermorelin, tesamorelin and CJC-1295 have their own records, and the comparison directory lists every head-to-head page.
Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.
Reported interactions
Sentences in which the compound is studied alongside another agent. Read the quotation: the word interaction can also be statistical.
-
Three independent reviewers searched the PubMed database using permutations of peptide search terms (BPC-157, TB-500, CJC-1295, MK-677 [ibutamoren], ipamorelin, and GHK-Cu) combined with musculoskeletal tissue search terms (bone, fracture, muscle, tendon, ligament, meniscus, and cartilage) following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.
Sourcepmid-42578445· quoted verbatim from the abstract -
The administration of either 5 or 30 µg of IPA for 21 days led to a significant and dose-dependent rise in food intake concomitant with a significant increase in the numbers of primary spermatocytes, secondary spermatocytes, and early spermatids compared to the control group.
Sourcepmid-38996787· quoted verbatim from the abstract
Other compounds in its class
Same class in the registry: GHRP-6. Each row shows what that compound's own record states; nothing is inferred across rows. Head-to-head evidence, where any exists, is on the comparison pages: Ipamorelin vs GHRP-6, Ipamorelin vs Sermorelin, Ipamorelin vs Tesamorelin.
| Compound | Tier | Publications | RCTs | Record |
|---|---|---|---|---|
| Ipamorelin | Human clinical trial | 63 | 2 | draft |
| GHRP-6 | Human clinical trial | 738 | 22 | draft |
Studied in combination
Whether any indexed study tested Ipamorelin together with the compounds it is commonly combined with. A count of zero is the finding, not a gap in this page.
- 3 indexed studies mention Ipamorelin together with CJC-1295. CJC-1295 + ipamorelin
- No indexed study tested Ipamorelin with Tesamorelin. Tesamorelin + ipamorelin
Is ipamorelin an approved medicine?
Registry facts only. Jurisdiction-level status, compounding categories and sport prohibitions need their own cited documents before they appear here.
- Registry entry
- Editorial synthesis from general knowledge · primary document to be added to the ledger
- Editorial synthesis from general knowledge · primary document to be added to the ledger
Open questions and limitations
What is genuinely unknown, stated plainly. A missing field is not evidence that the outcome is safe, effective, or established.
- No study in this record's ledger reports exclusion criteria for Ipamorelin.
Study limitations
- The current ledger contains only two human clinical studies, and their populations, routes, and research questions are not interchangeable.
- Most indexed records are preclinical, analytical, or mechanistic rather than human efficacy studies.
- No record in this ledger establishes an approved dose, a safe personal regimen, or a reliable conversion from animal dosing to humans.
- The evidence summary is based on indexed titles and abstracts; full-text review may change study classification or interpretation.
Questions people ask
How long is ipamorelin's half-life?
Randomized controlled trial, 1999: The PK parameters showed dose-proportionality, with a short terminal half-life of 2 hours, a clearance of 0.078 L/h/kg and a volume of distribution at steady-state of 0.22 L/kg.
Source pmid-10496658.
What is ipamorelin used for?
It has no approved use. It was developed to release growth hormone and tested for post-surgical gut recovery, where it failed. Outside the literature it is used for body composition, recovery and sleep, none of which has been measured in a human trial.
How long is ipamorelin's half-life?
About two hours in the human pharmacokinetic study, with growth hormone peaking around 40 minutes after dosing. Each injection produces one pulse.
What dose of ipamorelin did studies use?
Healthy volunteers received single intravenous infusions from 4.2 to 140 nmol/kg; surgical patients received 0.03 mg/kg intravenously twice daily for up to a week. Neither was chosen to optimise an outcome in healthy people. The 100 to 300 µg subcutaneous figures that circulate come from communities, not trials.
What are the side effects of ipamorelin?
The surgical trial reported it as tolerated with no signal distinguishing it from placebo over a week. Community reports describe flushing, headache, hunger, water retention and injection-site redness. Long-term effects, and effects on blood glucose and IGF-1 with repeated use, have not been studied.
Does ipamorelin raise cortisol?
In the 1998 animal work that gave it its reputation, it released growth hormone without the cortisol and ACTH rise seen with GHRP-6 and GHRP-2. That is the selectivity claim; it has not been tested in a long-term human study.
Ipamorelin vs CJC-1295: what is the difference?
Different receptors. Ipamorelin acts on the ghrelin receptor; CJC-1295 is a GHRH analogue. Both drive growth hormone release, which is why they are commonly combined. Three indexed papers mention both; none tested the combination for a user-relevant outcome.
Ipamorelin vs sermorelin?
Sermorelin is a GHRH analogue with a half-life of minutes that was once approved for children with growth hormone deficiency; ipamorelin acts on the ghrelin receptor with a two-hour half-life and was never approved. They are different classes, not alternatives within one.
Is ipamorelin FDA approved?
No. It has appeared on FDA's interim list of compounding bulk substances in the category flagged for significant safety concerns, and was discussed by FDA's compounding advisory committee in 2024. Its current category should be checked on FDA's live list.
Is ipamorelin banned in sport?
Yes. WADA lists growth hormone secretagogues, ipamorelin among them, under S2, prohibited at all times.
How long does ipamorelin take to work?
The growth hormone pulse is measured within the hour. Anything reported over weeks, sleep, recovery, body composition, is self-report from communities and has not been measured against placebo.
Does ipamorelin build muscle or burn fat?
No human trial has measured either. Growth hormone can do both in deficiency states; whether pulses from a secretagogue do so in healthy adults is unknown for ipamorelin.
Can ipamorelin be taken orally?
It is a peptide and is degraded in the gut; studies used intravenous infusion and communities use subcutaneous injection. An orally active secretagogue exists (ibutamoren), with a different profile.
How should ipamorelin be stored?
As a powder, refrigerated or frozen away from light; once dissolved in bacteriostatic water, commonly refrigerated and used within about four weeks. Discard cloudy or discoloured solution.
What blood tests are relevant?
IGF-1 as the downstream marker; fasting glucose and HbA1c because growth hormone opposes insulin; cortisol and prolactin to check the selectivity claim; thyroid and lipids as with any growth hormone exposure. No schedule has been validated for ipamorelin.
Has ipamorelin been tested in humans?
Twice: a pharmacokinetic study in healthy volunteers (1999) and a randomized phase 2 trial in 114 surgical patients (2014). Both are quoted on this page.
Which species has ipamorelin been studied in?
Humans, rats and pigs in the indexed literature, plus cell work. Findings do not transfer between species, and weight-normalised doses in particular do not scale linearly.
Sources
Full citations. Every claim above links to one of these by its id.
- 1Peptide Supplements and Their Therapeutic Applications in Sports Medicine.
pmid-42578445· · peer-reviewed - 2
- 3Evaluation of Research Grade Peptides Marketed Directly to Consumers Reveals Extensive Variability in Purity and Measured Abundance
doi-10-20944-preprints202604-1748-v1· · preprint - 4Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance.
pmid-41966639· · peer-reviewed - 5Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance
doi-10-20944-preprints202512-1011-v3· · preprint - 6Therapeutic peptides in gerontology: mechanisms and applications for healthy aging.
pmid-42021992· · peer-reviewed - 7Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.
pmid-41476424· · peer-reviewed - 8Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance
doi-10-20944-preprints202512-1011-v1· · preprint - 9
- 10
- 11Attenuation of Visceral and Somatic Nociception by Ghrelin Mimetics.
pmid-32801950· · peer-reviewed - 12
Show the remaining 18 sources
- 13A stable meta-carborane enables the generation of boron-rich peptide agonists targeting the ghrelin receptor.
pmid-30168238· · peer-reviewed - 14Doping control container for urine stabilization: a pilot study.
pmid-27497113· · peer-reviewed - 15
- 16
- 17
- 18Doping control analysis of seven bioactive peptides in horse plasma by liquid chromatography-mass spectrometry.
pmid-23318763· · peer-reviewed - 19Metabolism of growth hormone releasing peptides.
pmid-23101768· · peer-reviewed - 20Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileus.
pmid-27186127· · peer-reviewed - 21
- 22Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus.
pmid-19289567· · peer-reviewed - 23Growth hormone and growth hormone secretagogue effects on nitrogen balance and urea synthesis in steroid treated rats.
pmid-19231263· · peer-reviewed - 24Mechanism of ipamorelin-evoked insulin release from the pancreas of normal and diabetic rats.
pmid-15665799· · peer-reviewed - 25
- 26The influence of conformational restriction in the C-terminus of growth hormone secretagogues on their potency.
pmid-12204475· · peer-reviewed - 27The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats.
pmid-11735244· · peer-reviewed - 28Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers.
pmid-10496658· · peer-reviewed - 29Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats.
pmid-10373343· · peer-reviewed - 30
Reference card
- Compound
- Ipamorelin, ghrelin mimetics
- Evidence tier
- Human clinical trial
- Indexed publications
- 63 · 2 RCTs · 2 other clinical trials
- Approval
- not approved · max phase 2
- Routes reported
- intragastric, intranasal, intraperitoneal, intravenous, oral, subcutaneous
- Reviewed
- Adam Mirando, PharmD,
Study figures are as published in each source and are not recommendations. Print or save this card with its date.
Last reviewed and what changed
Newest first. These are the record's own revision dates, and the same dates feed the sitemap.
- · Reviewed by Adam Mirando, PharmD, on 2026-09-24.
- · Internal links added at first mention in the written guide; the storage claim block is stood in for by the written storage section.
- · Written guide added (9 editorial sections: quick answer, dosage chart, reconstitution, who should avoid, timeline, storage, monitoring, mistakes, five-compound comparison), FAQ expanded to 16, intent-driven H1 and title. Claim cards remain as the cited receipts beneath the prose.
- · Editorial sections added from general knowledge, labelled editorial synthesis: mechanism and development history (3), what is commonly reported outside the literature (2), FDA compounding and WADA status (2, primary documents pending). Indexing opened: pages publish as compiled.
- · Claims drafted extractively from 27 ledger sources by scripts/draft_claims.py: 25 claims, 22 evidence-table rows. Status researched -> draft.
- · Claims drafted extractively from 27 ledger sources by scripts/draft_claims.py: 22 claims, 22 evidence-table rows. Status researched -> draft.
- · Claims drafted extractively from 27 ledger sources by scripts/draft_claims.py: 22 claims, 22 evidence-table rows. Status researched -> draft.
- · Claims drafted extractively from 27 ledger sources by scripts/draft_claims.py: 33 claims, 22 evidence-table rows. Status researched -> draft.
- · Metadata refreshed by scripts/fetch_evidence.py --refresh-meta: tier animal-preclinical -> human-clinical-trial.
- · Evidence fetched from Europe PMC and ChEMBL by scripts/fetch_evidence.py; claims not yet written.