Ipamorelin
Also known as: NNC 26-0161, Aib-His-D-2-Nal-D-Phe-Lys-NH2
Ipamorelin (also called NNC 26-0161 or Aib-His-D-2-Nal-D-Phe-Lys-NH2) is a research peptide in the Growth Hormone Secretagogue class. Ipamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, the ghrelin receptor, on pituitary somatotrophs and hypothalamic neurons.
For research use only.
Key Facts
- CAS
- 170851-70-4
- Molecular Weight (MW)
- 711.9 g/mol
- Half-life
- Terminal half-life approximately 2 hours (human, intravenous)
- FDA status
- Not Approved
- Evidence level
- Limited Human Evidence
- Human dose established
- Yes
- Administration Route
- Intravenous (in all published human studies)
- Frequency
- Single infusion in the pharmacokinetic study; twice daily in the published ileus trial
- Last updated
- Sep 26, 2026
- Reviewed
- Aug 30, 2026
- Targets
- GHSR
Vendor price snapshot
Each vendor counts once, at the median price per mg of its own listings; the typical range is the middle half of vendors. From public vendor listings collected between Dec 2025 and Oct 2026, so confirm the live price on the vendor site. Peptide Library does not sell peptides.
- Vendors listing this peptide
- 43
- Listed offers
- 98
- Median price per mg
- $5.76/mg
- Typical $5.00–$8.00/mg
Research summary
Pentapeptide ghrelin-receptor agonist noted for GH release with relatively less ACTH/cortisol than older GHRPs. Not FDA-approved. WADA S2 (named).
Peptide Library's Ipamorelin profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Ipamorelin dosage chart
Ipamorelin has been dosed in humans, but only intravenously and not for the purpose it is generally sold for. The published pharmacokinetic study infused 4.21–140.45 nmol/kg over 15 minutes in healthy male volunteers, and two completed phase 2 trials gave it intravenously for post-operative ileus. No published human study supports subcutaneous microgram dosing for growth-hormone or body-composition purposes.
| Human dosing established | Yes |
|---|---|
| Route | Intravenous (in all published human studies) |
| Frequency | Single infusion in the pharmacokinetic study; twice daily in the published ileus trial |
| Duration studied | Single 15-minute infusion (pharmacokinetic study) |
| Half-life | Terminal half-life approximately 2 hours (human, intravenous) |
| Evidence level | Limited Human Evidence |
| Last reviewed | 2026-09-05 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| Human pharmacokinetic and pharmacodynamic study (Gobburu et al., 1999)Clinical trial · Human dose-escalation PK/PD study | Healthy male volunteers, 8 per dose level | 4.21, 14.02, 42.13, 84.27 and 140.45 nmol/kg (dose-escalation) | Intravenous infusion over 15 minutes | Single dose per level | Single 15-minute infusion | Ipamorelin pharmacokinetics and growth hormone release | Gobburu JV et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res. 1999. |
| NCT01280344 — phase 2 dose-finding trial, completed 2014, no results postedClinical trial · Phase 2 randomised placebo-controlled trial | Patients recovering gastrointestinal function after surgery (n=320) | 0.03 mg/kg twice daily, 0.06 mg/kg twice daily or 0.06 mg/kg three times daily (dose-finding arms) | Intravenous | — | — | Recovery of gastrointestinal function | NCT01280344 — Safety and Efficacy of Ipamorelin Compared to Placebo for the Recovery of Gastrointestinal Function |
| Phase 2 proof-of-concept trial in post-operative ileus (Beck et al., 2014; NCT00672074)Clinical trial · Phase 2 multicentre double-blind randomised placebo-controlled trial | Adults after small or large bowel resection (117 enrolled, 114 analysed) | 0.03 mg/kg | Intravenous infusion | Twice daily | Postoperative day 1 to day 7, or until discharge | Time to first tolerated solid meal (no significant difference versus placebo, p = 0.15) | Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus. Int J Colorectal Dis. 2014. |
Where sources disagree
- Every published human study of ipamorelin used intravenous administration. The 200–300 mcg subcutaneous, once-to-three-times-daily protocols published by vendors and reference sites have no published human study behind them, and intravenous and subcutaneous dosing are not interchangeable.
- Doses in the human pharmacokinetic study are reported in nmol/kg and scale with body weight. They are not equivalent to a fixed microgram dose, and this profile does not convert them into one.
- Both completed phase 2 trials were in post-operative ileus, a hospital indication. The first (NCT00672074) was published by Beck et al. in 2014 and found no significant difference from placebo on its efficacy endpoints; the larger dose-finding trial (NCT01280344) has posted no results. There is no published human efficacy evidence for growth-hormone or body-composition use.
Reconstitution
Common research vial sizes: 2 mg, 5 mg, 10 mg.
| Vial | Bacteriostatic water | Concentration | Per 0.01 mL |
|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL | 25 mcg per 0.01 mL |
| 10 mg | 2 mL | 5 mg/mL | 50 mcg per 0.01 mL |
These figures are arithmetic only — they convert a vial and a volume into a concentration. They are not a recommendation to take any dose.
Calculate reconstitution & dose →Handling & administration
- Reconstitution Guide
- Add 2 mL bacteriostatic water per 5 mg vial.
- Injection Sites
- AbdomenThigh
- Concentration Example
- 5 mg + 2 mL → 2.5 mg/mL
- Timing Notes
- Morning and/or evening
- Expected Onset
- 1–2 weeks
How to reconstitute Ipamorelin
- Check the vial size and diluent volume. The profile example for Ipamorelin is: Add 2 mL bacteriostatic water per 5 mg vial.
- Swab both vial stoppers and draw the bacteriostatic water into a sterile syringe.
- Add the water slowly down the inside wall of the peptide vial so it does not jet onto the powder, then swirl gently until the solution is clear. Do not shake.
- Record the resulting concentration: 5 mg + 2 mL → 2.5 mg/mL.
- Label the vial with the date and concentration, refrigerate it (see Storage & stability below), and use the calculator preset to convert a dose in mcg into syringe units.
Sequence & molecular data
| Molecular formula | C38H49N9O5 |
|---|---|
| Molecular weight | 711.9 g/mol |
| CAS number | 170851-70-4 |
| Half-life | ~2 hours |
| Appearance | White lyophilized powder |
| Formulation | Lyophilized Powder |
| PubChem CID | 9831659 |
| FDA UNII | Y9M3S784Z6 |
| ChEMBL | CHEMBL58547 |
| DrugBank | DB12370 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Ipamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, the ghrelin receptor, on pituitary somatotrophs and hypothalamic neurons. It is notable within the class for selectivity: in published human and animal studies it releases growth hormone with little effect on cortisol, prolactin or aldosterone, and without the marked appetite stimulation characteristic of GHRP-6. Because it acts through the ghrelin receptor rather than the GHRH receptor, its effect is additive with GHRH analogs, which is the pharmacological basis for combining the two classes. It is not approved for any use.
Origin
Synthetic pentapeptide GHS.
Targets
Studies
- The influence of ghrelin agonist ipamorelin acetate on the hypothalamic-pituitary-testicular axis in a cichlid fish, Oreochromis mossambicus
- The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced weight loss in ferrets: Anamorelin also exhibits anti-emetic effects via a central mechanism
- Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions
- Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians
- Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance
Regulatory & research status
Ipamorelin is not an FDA-approved product. It is sold for laboratory research and has no approved medical use.
| FDA status | Not Approved |
|---|---|
| Availability | Research-Only |
| WADA (sport) | Banned in Sport |
| Library classification | Research-Only |
Benefits
Ipamorelin side effects
Ipamorelin has only limited human data, so the list below is incomplete and its side-effect profile is not well established.
Side Effects
- Headache
- Flushing
- Water retention
Contraindications
- Avoid with diabetes
- Not recommended during pregnancy
Stacking
Common stacking partners
Combinations that include Ipamorelin, with the proposed rationale, an evidence grade and what is not established, are catalogued in the peptide stacks directory.
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Ipamorelin: frequently asked questions
What is Ipamorelin?
Pentapeptide ghrelin-receptor agonist noted for GH release with relatively less ACTH/cortisol than older GHRPs. Not FDA-approved. WADA S2 (named). Ipamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, the ghrelin receptor, on pituitary somatotrophs and hypothalamic neurons. It is notable within the class for selectivity: in published human and animal studies it releases growth hormone with little effect on cortisol, prolactin or aldosterone, and without the marked appetite stimulation characteristic of GHRP-6.
What are the side effects of Ipamorelin?
Ipamorelin has only limited human data, so its side-effect profile is not well established. Effects recorded on this profile include headache, flushing and water retention. Cautions recorded on this profile: avoid with diabetes and not recommended during pregnancy. It is on the WADA Prohibited List for athletes. This is reference information, not medical advice.
How does Ipamorelin work?
Ipamorelin is a synthetic pentapeptide agonist at growth hormone secretagogue receptor 1a, the ghrelin receptor, on pituitary somatotrophs and hypothalamic neurons. It is notable within the class for selectivity: in published human and animal studies it releases growth hormone with little effect on cortisol, prolactin or aldosterone, and without the marked appetite stimulation characteristic of GHRP-6.
Is Ipamorelin FDA approved?
No. Ipamorelin is not approved by the FDA for any indication and is categorised as research-only. It has not been reviewed for safety or efficacy as a medicine, and published research should be read as investigation rather than established use.
What is the half-life of Ipamorelin?
Reported half-life for Ipamorelin is ~2 hours. Half-life describes how long the compound persists in circulation, not how long any effect lasts, and published figures vary with route of administration, formulation and the population studied.
Is Ipamorelin banned in sport?
Ipamorelin is recorded here as prohibited in sport. Athletes subject to anti-doping rules should check the current WADA Prohibited List directly, since it is revised annually and classifications change.
What peptides are similar to Ipamorelin?
Compounds most often compared with Ipamorelin include GHRP-6, GHRP-1, Pralmorelin (GHRP-2) and Hexarelin (Examorelin). They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
How long does Ipamorelin take to show effects in research protocols?
The research protocol on this profile lists an expected onset of 1–2 weeks. This is a protocol note describing when studies and researchers report observing changes, not a measured clinical outcome, and it varies with the model, dose and endpoint studied.
Where is Ipamorelin administered in research protocols?
Research protocols on this profile use subcutaneous administration, with recorded sites including abdomen, thigh. Site rotation and sterile technique are standard practice in the research literature; this describes protocol conditions and is not guidance for use.
References
- WADA Prohibited List 2026External reference
- The influence of ghrelin agonist ipamorelin acetate on the hypothalamic-pituitary-testicular axis in a cichlid fish, Oreochromis mossambicus — Anim Reprod Sci, 2024External reference
- The growth hormone secretagogue receptor 1a agonists, anamorelin and ipamorelin, inhibit cisplatin-induced weight loss in ferrets: Anamorelin also exhibits anti-emetic effects via a central mechanism — Physiol Behav, 2024External reference
- Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions — J Am Acad Orthop Surg Glob Res Rev, 2026External reference
- Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians — Am J Sports Med, 2026External reference
- Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance — Sports Med, 2026External reference
Related research, comparisons & guides
- Ipamorelin Dosage: What the Research Reports and How the Vial Math Works
- CJC-1295 and Ipamorelin: Why the Pairing Exists and What the Vial Math Looks Like
- Hexarelin: The Most Potent GHRP, and Why That Is Not Simply Good
- Ipamorelin vs Tesamorelin: Two Receptors, One Approved Drug
- Tesamorelin vs CJC-1295: Same Receptor, Different Clock
- Peptides for Muscle Growth: Separating Mechanism From Evidence
- Tesamorelin vs. Sermorelin: Same Family, Different Standing
- MK-677 (Ibutamoren): An Oral Secretagogue That Is Not a Peptide
- GHRP-2 (Pralmorelin): The Middle Option in the GHRP Family
- Ipamorelin Side Effects: What Selectivity Actually Removes
- Best Time to Inject: When Timing Matters and When It Does Not
- Peptides for Sleep: Three Candidates, Very Little Evidence
- Ipamorelin vs. Sermorelin: Two Receptors, One Outcome
- Sermorelin Side Effects: What the Label Recorded
- Sermorelin Before and After: What Results Are Plausible and What Photos Hide
- SARMs vs Peptides: Different Molecules, Different Risks
- Sermorelin Tablets: Why Oral and Sublingual Forms Are a Hard Sell
- CJC-1295
- Sermorelin
- Peptide stacks: combinations by research goalStacks
- Peptide dosage chart: dose, route and frequencyCategory
- Peptide calculator with the Ipamorelin preset
- How to store peptides before and after reconstitution
Related peptides
Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Sep 26, 2026 · Version 6
This Ipamorelin profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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