Compound record · Growth hormone axis

Ipamorelin

Also Ipa · NNC 26-0161 · Ipamorelin acetate · CJC/Ipa

Selective ghrelin-receptor agonist (GH secretagogue pentapeptide)

Growth hormone axisEvidence · PreliminaryEarly-stage human studiesWADA · Prohibited at all times

Selective GH secretagogue that failed its only published efficacy trial

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Record reviewed 1 September 2026 · 6 references

In the AERVYN range

1 pen carries Ipamorelin

Single-compound pen
Ipamorelin
Peptide pen · 10 mg / 3 mL
£175 · In stock

Class: Selective ghrelin-receptor agonist
Human trials: Phase 1 (n = 8) and two Phase 2 ileus trials — no benefit shown
Half-life: ≈ 2 hours; one GH pulse per dose
Route: Intravenous in trials; subcutaneous in unregulated use
Status: Not authorised anywhere; WADA-prohibited (S2)

01 Overview

What Ipamorelin is

Summary

Ipamorelin is a synthetic five-amino-acid peptide developed by Novo Nordisk that releases growth hormone by activating the ghrelin receptor, with little effect on cortisol or prolactin. Its human development — a Phase 1 pharmacokinetic study and two Phase 2 trials for post-operative bowel paralysis — ended after the published trial showed no benefit over placebo. It has never been authorised as a medicine and is sold as an unregulated research chemical, usually marketed with CJC-1295 for muscle, recovery and sleep despite no clinical trials for any of those uses.

Mechanism

Activates the growth-hormone-secretagogue (ghrelin) receptor GHS-R1a on pituitary cells and in the hypothalamus, producing a single pulse of GH release that peaks about 40 minutes after a dose; unlike older GH-releasing peptides it does not meaningfully raise ACTH, cortisol or prolactin. Its half-life after intravenous dosing is around two hours, and as a ghrelin mimetic it may also increase appetite and gut motility.

Routes studiedSubcutaneous injection, Intravenous

Anti-dopingProhibited at all times

02 Evidence by goal

What has been shown, for which goal

Grades follow one scale across the site. Preliminary overall means: early-phase human data or case series; findings need replication.

Muscle & recovery
Insufficient
No human study has measured muscle mass, strength or recovery; the only human data are GH release in eight volunteers and a bowel-recovery trial that showed no benefit.
Injury & recovery support
Insufficient
No human data for injury or tissue healing; claims rest on the general role of GH in tissue growth.
Sleep
Insufficient
Marketed for deeper sleep on the basis that GH is normally released during slow-wave sleep; no trial has measured sleep with ipamorelin.
Fat loss / body composition
Insufficient
No human body-composition data; as a ghrelin mimetic it may increase appetite rather than reduce fat.

03 Regulatory status

Where it is authorised, and for what

Status is recorded per jurisdiction from regulator sources and reviewed by hand. It is never inferred from another region's decision.

United Kingdom

Not authorised

Not authorised as a medicine; sold only as an unregulated 'research chemical'.

No MHRA licence has ever been applied for. Products sold online are labelled 'not for human consumption' and sit outside medicines quality controls.

StatusNot authorised

Status last reviewed1 September 2026

SourceOur maintained database — never inferred

04 Dosing research

What the evidence says about exposure

Published human studies and the doses, routes and durations they used — reported as research information, not a recommendation.

Research information — not a recommendation. These are the exposures used in published human studies, reported so you can see what has been tested. They are not dosing instructions and do not apply to any individual.

Study 01

Pharmacokinetic–pharmacodynamic study of intravenous ipamorelin in healthy men

Gobburu JVS et al., Pharm Res 1999;16:1412–1416

Phase 11999

Design: Open-label, escalating single intravenous infusions
Population: Healthy male volunteers
Participants: n = 8
Duration: Single doses
Route: Intravenous

Doses studied: Five escalating single intravenous infusions
Outcome at this exposure: Dose-proportional kinetics with a terminal half-life of about two hours; each dose produced a single GH release episode peaking at about 0.67 hours. Variability in GH response between individuals exceeded variability in drug levels.
Adverse events observed: Not reported in detail in the abstract; the study was designed to characterise kinetics rather than safety.

Study 02

Phase 2 proof-of-concept — ipamorelin for post-operative ileus after bowel resection

Beck DE et al., Int J Colorectal Dis 2014;29:1527–1534 (Ipamorelin 201 Study Group) · Source

Phase 22014

Design: Randomised, double-blind, placebo-controlled, multicentre
Population: Adults recovering from partial bowel resection (114 in the analysis populations)
Participants: n = 117
Duration: Up to 7 days or hospital discharge
Route: Intravenous

Doses studied: 0.03 mg/kg intravenously twice daily from post-operative day 1
Outcome at this exposure: Median time to first tolerated meal 25.3 h with ipamorelin vs 32.6 h with placebo (p = 0.15) — not statistically significant; no significant differences in key or secondary efficacy outcomes.
Adverse events observed: Well tolerated; treatment-emergent adverse events in 87.5% vs 94.8% (mostly surgery-related) with no safety signal attributable to ipamorelin.

No published human study has given ipamorelin subcutaneously or for longer than seven days, and none has measured GH-related outcomes such as body composition. A second, larger Phase 2 dose-finding trial in post-operative ileus (NCT01280344, n = 320) completed in 2014 without published results, and Helsinn discontinued development. The 200–300 µg subcutaneous doses used in online protocols have never been evaluated in a trial.

05 Safety

Adverse effects and contraindications

Common effects seen in trials or reports, serious effects that warrant urgent review, and conditions under which use is not appropriate or needs assessment.

Common adverse effects

Headache
Flushing or warmth after injection
Increased appetite (ghrelin-receptor effect)
Transient rise in blood glucose
Injection-site pain or redness
Nausea
Light-headedness
Water retention with repeated dosing

Serious adverse effects

Glucose intolerance or diabetes with sustained GH elevation (theoretical; no long-term data)
Fluid retention, joint pain and carpal tunnel syndrome (GH excess)
Possible acceleration of an existing malignancy
Immunogenicity and allergic reactions — the specific FDA safety concern for compounded ipamorelin
Contamination or wrong-dose harms from unregulated vials
Unknown effects of chronic use — no human exposure beyond seven days has been published

Contraindications

CancerDo not use
Raises GH and IGF-1, which are growth factors; any active or previous malignancy should be regarded as excluding use.
Acromegaly or pituitary tumourDo not use
Further stimulation of GH release in acromegaly or with a pituitary tumour is inappropriate.
DiabetesCaution
GH pulses raise glucose transiently and sustained use may worsen insulin resistance; no glucose data exist beyond seven days.
Hormonal disorderCaution
Requires a functioning pituitary; pituitary or adrenal disorders need endocrine assessment first.
Cardiovascular diseaseCaution
Ghrelin-receptor agonists influence heart rate, blood pressure and fluid balance; there are no cardiovascular safety data for repeated use.

Do not use = should not be used · Caution = needs assessment

06 Interactions

Medicine classes that need review

Grouped by how seriously the combination should be taken. Class labels match the medicines questionnaire in the assessment.

Major
Moderate
Minor

Major

Combination should be reviewed by a prescriber before use.

Growth hormone
Somatropin
Duplicate GH-axis stimulation with additive IGF-1 exposure; injected GH also suppresses the pituitary response ipamorelin depends on.

Moderate

Monitoring or dose review is usually advised.

Insulin
Lantus, NovoRapid, Humalog, Tresiba
GH opposes insulin; glucose monitoring is advised if used repeatedly.
Corticosteroid
Prednisolone, dexamethasone, hydrocortisone
Glucocorticoids blunt GH release and raise glucose; GH increases cortisol clearance, so replacement doses may need review.

Minor

Generally compatible; awareness is sufficient.

Sulfonylurea
Gliclazide, glimepiride, glipizide
Glucose control may shift; monitoring advised.
Other glucose-lowering medicine
Metformin, SGLT2 inhibitors, DPP-4 inhibitors
Glucose-lowering effect may be partly offset; monitoring advised.
Testosterone / anabolic hormone
Testosterone gel or injection
Frequently combined in 'performance' regimens; androgens amplify IGF-1 responses to GH, and there are no safety data for the combination.
Thyroid hormone
Levothyroxine, liothyronine
Thyroid status affects the GH response; ensure replacement is stable.

07 Pregnancy & breastfeeding

Status in pregnancy

Insufficient data

No human or published animal reproductive data. Use in pregnancy or while breastfeeding cannot be supported for an unlicensed product with no safety database.

08 Monitoring

What is usually monitored

Parameters that trials and product information track. A clinician decides what applies to an individual.

01IGF-1 at baseline and periodically
02Fasting glucose and HbA1c
03Weight and appetite changes
04Blood pressure, swelling and joint symptoms
05Injection-site reactions and any signs of allergy
06Age-appropriate cancer screening

09 Combinations

What is known about combining it

Notes on pairing with other compounds in the directory: whether the combination has been studied in people, and where mechanisms overlap.

CJC-1295
Limited human data
Overlap · Both raise GH and IGF-1 — ipamorelin via the ghrelin receptor and CJC-1295 via the GHRH receptor.
The most commonly co-used pair ('CJC/Ipa'). GHRH and ghrelin-receptor agonists release GH synergistically in short physiology studies, which is the rationale, but no clinical trial has tested this combination for any outcome or its safety; the FDA has described it as an unapproved novel drug combination.
Sermorelin
No human studies
Overlap · Both raise GH and IGF-1 via complementary receptors.
Commonly co-marketed as 'Sermorelin/Ipamorelin'; no clinical trial has tested the combination.
Tesamorelin
No human studies
Overlap · Both raise GH and IGF-1 via complementary receptors.
No human data; additive IGF-1 exposure and glucose effects are expected.
Somatropin
No human studies
Overlap · Duplicate GH-axis stimulation; injected GH suppresses the pituitary response ipamorelin depends on.
No rationale or data; IGF-1 and glucose effects would be additive.
IGF-1 LR3
No human studies
Overlap · Additive IGF-1 exposure from two unlicensed products.
No human data; IGF-1 LR3 has never been studied in people.
Tirzepatide
No human studies
No human studies of GH secretagogues combined with incretin medicines; GH raises glucose while incretins lower it.
BPC-157
No human studies
Marketed together as 'recovery' stacks; no human data for the combination and BPC-157 lacks human efficacy data.
TB-500
No human studies
No human data on the combination; TB-500 itself has no human efficacy data.

Discuss any proposed combination with a qualified healthcare professional.

10 Source considerations

Supply, quality and legitimacy

How the compound reaches people in practice, and what that means for product quality.

01Not a licensed medicine anywhere and not eligible for US pharmacy compounding after the 2023–2024 FDA review; the only supply is unregulated 'research chemical' vials.
02'CJC/Ipa' blends are sold as a single vial with undisclosed or unverified ratios — independent testing of research-chemical peptides frequently finds mislabelled identity and potency.
03The FDA cited immunogenicity and reported serious adverse events in keeping ipamorelin in Category 2 for outsourcing facilities.
04Products labelled 'not for human consumption' carry no sterility, endotoxin or potency assurance.

11 Questions for your clinician

Take these to your appointment

Specific to this compound. The personal assessment adds questions drawn from your own history and medicines.

01Is there any documented GH deficiency that would justify GH-axis stimulation, and if so why not a licensed treatment?
02What outcome are we expecting, given that no human study has measured muscle, recovery or sleep with ipamorelin?
03What are my baseline IGF-1, glucose and HbA1c, and how often would they be rechecked?
04Do I have any cancer, pituitary, diabetes or cardiovascular history that changes the risk?
05What do we know about the identity and purity of the specific product, especially if it is a CJC/Ipa blend?
06Am I subject to anti-doping rules in any sport?

The personal assessment tailors this list to your responses.

12 Alternatives

Compounds with stronger evidence or firmer regulatory footing

Listed for overlapping goals. Whether any is appropriate depends on your history — the assessment maps that for you.

13 References

Sources behind this record

Regulator documents and peer-reviewed publications used to derive every grade and statement above.

01Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol 1998;139:552–561
02Gobburu JVS et al. Pharmacokinetic–pharmacodynamic modeling of ipamorelin in human volunteers. Pharm Res 1999;16:1412–1416
03Beck DE et al. Ipamorelin for post-operative ileus after bowel resection (Phase 2). Int J Colorectal Dis 2014
04ClinicalTrials.gov NCT01280344 — Phase 2 dose-finding study of ipamorelin in post-operative ileus (completed 2014, no results posted)
05FDA — Bulk drug substances nominated for use in compounding under section 503A (category lists)
06WADA Prohibited List — S2 peptide hormones, growth factors, related substances and mimetics

The Peptide Checkup provides educational information and a structured summary of published research and regulatory status. It is not medical advice, does not diagnose or treat any condition, and does not replace a consultation with a qualified healthcare professional.

Personal assessment

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