Compounds / Ipamorelin
Ipamorelin
Also known as: Ipamorelin; NNC 26-0161; Aib-His-D-2-Nal-D-Phe-Lys-NH2; CAS 170851-70-4
Primary research focus: Growth hormone axis research (selective ghrelin-receptor agonist; GH secretagogue)
Last updated July 2026 · Reviewed against FDA labeling and published research.
What is Ipamorelin?
Ipamorelin is a synthetic pentapeptide that selectively stimulates growth hormone (GH) release from the pituitary by activating the ghrelin receptor. Its defining feature is selectivity: at GH-releasing doses it does not meaningfully raise cortisol, prolactin, or appetite, distinguishing it from older peptides such as GHRP-6. It reached Phase 2 clinical testing but was never approved, and its US compounding status is in regulatory flux.
Ipamorelin is a selective agonist of the growth hormone secretagogue receptor (GHS-R1a), the ghrelin receptor, on pituitary somatotrophs. Receptor activation drives Gq/phospholipase C signaling with IP3 and calcium release, prompting a pulsatile release of stored growth hormone that mimics natural ghrelin. Because it acts on the pituitary's own GH reserves and preserves feedback, and because of its selectivity, it does not significantly stimulate ACTH, cortisol, prolactin, or the gonadotropins at GH-releasing doses.
How it’s supplied
Not an FDA-approved or commercially available medicine. It is sold as a research-grade lyophilized peptide for reconstitution; such products are not FDA-reviewed for potency or sterility, and legitimate compounded access is limited by its regulatory status.
Dosage Chart
Units shown are for a U-100 insulin syringe (100 units = 1 mL), calculated from the vial size and BAC water you select. Always confirm against your prescription and your syringe markings.
| Phase | Dose | Frequency | Notes |
|---|---|---|---|
| Weeks 1-2 | 100mcg | 1x Daily | — |
| Weeks 3-4 | 150mcg | 1x Daily | — |
| Weeks 5-8 | 200mcg | 1x Daily | — |
| Weeks 9-12 | 250mcg | 1x Daily | — |
- Rotate injection sites to reduce irritation and lipohypertrophy
- Not for use during pregnancy or breastfeeding
- Do not exceed the recommended dose to try to speed results
- Typically administered on an empty stomach at bedtime to align with natural nocturnal GH releases
Potential Benefits and Side Effects
Effects reported in published research. Not a promise of results, and not medical advice.
- Reported in research; not an approved therapy.
- Selective, pulsatile stimulation of endogenous growth hormone with downstream IGF-1 elevation.
- Cleaner side-effect profile than GHRP-2 and GHRP-6, without cortisol, prolactin, or appetite effects.
- Studied for postoperative gut motility in human trials.
- Commonly paired with a GHRH analog in research protocols to amplify GH pulses.
- Reported effects are generally mild: head-flush and mild headache.
- No significant cortisol or prolactin shifts at GH-releasing doses.
- Class effects of GH elevation (water retention, joint or tingling symptoms, glucose changes) are possible.
- Long-term human safety data are lacking.
Warnings and contraindications
Important safety information. This is not exhaustive — read the full prescribing information and consult your prescriber or pharmacist.
- No FDA-approved labeling exists; the following reflect the compound's status and class effects, not an FDA label.
- It is not FDA-approved; while cleaner than older secretagogues, long-term human outcome data are lacking.
- Raising GH and IGF-1 carries class concerns, including glucose intolerance and insulin resistance, fluid retention, and joint symptoms.
- It is prohibited in sport under the WADA Prohibited List (S2).
- Its compounding status is unsettled; much online supply is from unregulated research-chemical vendors.
- Safety in pregnancy and breastfeeding has not been established.
- Not established as a drug; no FDA labeling. Precautionary considerations include active or suspected malignancy (GH/IGF-1 biology), elevated baseline IGF-1 or acromegaly, and known hypersensitivity.
Reconstitution Steps
How to prepare the lyophilized vial. Confirm specifics with your pharmacist or prescriber.
- Confirm the amount of peptide in the vial and the volume of diluent you intend to use before starting.
- Wash your hands and gather supplies: the lyophilized vial, the diluent (typically bacteriostatic water), an alcohol swab, and a sterile syringe.
- Let the vial and diluent reach room temperature if they were refrigerated or frozen.
- Wipe the rubber stopper of both the peptide vial and the diluent vial with a fresh alcohol swab and let them air dry.
- Draw the intended diluent volume into the syringe.
- Insert the needle into the vial and slowly release the diluent down the inside wall rather than directly onto the powder, to avoid foaming.
- Do not shake. Gently swirl or roll the vial until fully dissolved.
- Inspect the solution: it should be clear and colorless with no visible particles. Do not use if cloudy or containing particles.
- Note the resulting concentration (amount divided by diluent volume) so it matches the reconstitution calculator on this page.
- Label the vial with the reconstitution date and store as directed under reconstituted storage.
US regulatory status
Classifications are public record but can change. For reference only, not legal advice.
Development: Ipamorelin was developed by Novo Nordisk (development code NNC 26-0161) and first characterized by Raun and colleagues in 1998 as the first selective growth hormone secretagogue. It was studied in humans, primarily for postoperative ileus and gut motility rather than anti-aging, and human pharmacokinetic and Phase 2 data exist, but the clinical program was discontinued and it never reached approval. In the 2023 FDA action ipamorelin was placed in Category 2. In the 2026 reclassification it is generally counted among the peptides moving back toward Category 1, though its status has been described as less certain than others and is handled differently across the 503A and 503B pathways; the FDA advisory committee review is the key near-term event.
Notes: Ipamorelin is not FDA-approved. It was placed on the FDA Category 2 list in 2023. In the 2026 reclassification it is generally grouped with the peptides being returned to Category 1 for 503A compounding, though reporting indicates its status is less settled than others and 503B outsourcing remained restricted; this should be verified against the current FDA list and advisory committee outcome. It is prohibited in sport (WADA) and is not a controlled substance. (Status current as of mid-2026.)
International status
Pharmacokinetics
Storage and handling
Important Notes
Practical considerations for consistency and safety.
- Ipamorelin is the most selective of the common GH secretagogues: it does not meaningfully raise cortisol, prolactin, or appetite, unlike GHRP-2 and GHRP-6.
- It reached Phase 2 trials (Novo Nordisk) but was discontinued and never approved.
- Its compounding status is in flux and is handled differently across 503A and 503B; verify the current FDA classification.
- It is banned in sport (WADA S2).
- Research-grade material varies in identity and purity.
Lifestyle Factors
- In research it is often timed to sleep or activity and combined with a GHRH analog to shape GH pulses.
- Human lifestyle interactions beyond research use are not well characterized.
References
Related compounds
Important disclaimer
This page is an educational reference, not medical advice, a diagnosis, or a treatment recommendation, and not a substitute for your prescriber or pharmacist. Approval and regulatory status varies by compound and can change. Always confirm against current prescribing information and consult a qualified healthcare professional before making any decision about a medication.