Ipamorelin
NNC 26-0161
Selective GH pulse with minimal cortisol or prolactin effect
Overview
Ipamorelin is a pentapeptide ghrelin-receptor (GHS-R) agonist — a growth-hormone secretagogue that triggers GH release through the same receptor as the natural hunger hormone ghrelin, but via a pathway entirely separate from GHRH. Its defining feature is selectivity: in pharmacology studies it stimulates growth-hormone release with little to no increase in cortisol, prolactin, or aldosterone, distinguishing it from older, less specific secretagogues such as GHRP-6.
Because it acts on a different receptor than GHRH analogs, ipamorelin is frequently paired with a GHRH peptide (most often CJC-1295) so the two pathways combine for a larger, cleaner GH pulse than either produces alone. Its roughly two-hour half-life makes it short-acting enough to respect natural pulsatility while lasting longer than a GHRH-only signal. Unlike GHRP-6, it does not provoke a strong hunger response, which is one reason it is the more widely used ghrelin-class peptide.
Ipamorelin is not an approved medicine. The dosing ranges and schedules below reflect widely-reported community protocols and published receptor pharmacology, and are provided strictly as a research reference rather than medical advice.
Key parameters
- Dose range
- 100–300 mcg per dose (community)
- Frequency
- 1–3× daily
- Half-life
- ~2 hours
- Route
- Subcutaneous
- Vial sizes
- 5 mg · 10 mg
- Regulatory status
- Not approved; research use only.
Mechanism of action
Ghrelin receptor (GHS-R1a) agonism
Activates the growth-hormone secretagogue receptor on pituitary somatotrophs and the hypothalamus, evoking a pulse of growth-hormone release.
Selective GH release
Stimulates GH with minimal effect on cortisol, prolactin, or ACTH in pharmacology studies — the basis for its 'clean' reputation relative to GHRP-6.
Complementary to GHRH signaling
Because it works through the ghrelin pathway rather than the GHRH receptor, it adds to (rather than overlaps with) GHRH-analog stimulation when stacked.
Downstream IGF-1 elevation
The GH released in response drives hepatic IGF-1 production, the principal mediator of the recovery and body-composition effects sought from the GH axis.
Dosing protocol & phases
| Phase | Weeks | Dose | Notes |
|---|---|---|---|
| Standard (community) | Ongoing | 100–300 mcg per injection | Often dosed 1–3× daily; ~200–300 mcg is a frequently-cited per-dose 'saturation' amount. |
| Timing pattern | Ongoing | 200 mcg pre-bed (± post-workout, ± fasted morning) | Timed to natural pulses and away from food; community-derived, not clinically established. |
Reconstitution guide
For educational and research reference only. Not intended for human consumption, not medical advice. Compounds discussed are sold and used for laboratory research purposes only.
5 mg vial + 3 mL bacteriostatic water
Concentration1,666.7 mcg/mL · 1.667 mg/mL
| Target dose | Draw volume | U-100 units |
|---|---|---|
| 100 mcg | 0.06 mL | 6 |
| 200 mcg | 0.12 mL | 12 |
| 300 mcg | 0.18 mL | 18 |
Keeps a 100 mcg dose at a readable 0.06 mL (6-unit) draw; the 300 mcg dose is 0.18 mL (18 units).
10 mg vial + 3 mL bacteriostatic water
Concentration3,333.3 mcg/mL · 3.333 mg/mL
| Target dose | Draw volume | U-100 units |
|---|---|---|
| 200 mcg | 0.06 mL | 6 |
| 300 mcg | 0.09 mL | 9 |
Higher-strength mix for a larger vial; doses stay small but readable.
Reconstitution calculator
Pre-filled with Ipamorelin's vial sizes. Adjust the water volume and target dose to see the exact draw, with warnings for doses that are hard to measure or won't fit a syringe.
At 1,666.7 micrograms per millilitre, a 100 microgram dose is 0.06 millilitres, or 6 units on a U-100 syringe, giving 50 doses per vial.
Supplies needed
Affiliate disclosure: we may earn a commission from supplier links, at no extra cost to you. For research and educational use only.
Recommended supply
Ipamorelin — research vial
From our verified partner Dynotides, with a third-party certificate of analysis per batch.
Injection supplies
- View
Bacteriostatic water
Diluent for reconstituting lyophilized vials.
- Buy
Insulin syringes (U-100)
0.3–0.5 mL, 29–31 G for accurate small draws.
- Buy
Alcohol prep pads
Sterile swabs for the vial stopper and site.
- Buy
Sharps container
Safe disposal of used needles.
- Buy
Storage fridge
Keeps reconstituted vials at 2–8 °C.
- Buy
Insulated travel case
Cooled, TSA-friendly case for travel.
Missed-dose guidance
With a short half-life, a missed dose is generally skipped rather than taken late, and the next scheduled dose is administered normally. Doses are not stacked to compensate. No approved-label guidance exists.
Side effects & safety
| Category | Effect | Trial incidence |
|---|---|---|
| Injection site | Redness, itching, or transient swellingMost commonly reported; usually mild. | — |
| Neurological | Headache or lightheadedness | — |
| Fluid balance | Mild water retentionGenerally less than with long-acting GH-axis compounds. | — |
| General | Drowsiness after a bedtime dose | — |
| Gastrointestinal | Mild, transient hungerMuch weaker than GHRP-6 owing to ipamorelin's selectivity. | — |
Clinical trials & evidence
Raun et al. discovery pharmacology
PreclinicalAcute · Rats, swine, and in vitro pituitary cells
Characterized ipamorelin as the first selective GH secretagogue: it released GH with a potency comparable to GHRP-6 but, unlike GHRP-6, did not meaningfully raise ACTH or cortisol even at high doses.
Trial identifier needs verification
Beck et al. post-operative ileus trial
Phase 2Postoperative days 1–7 (or until discharge) · Adults undergoing open or laparoscopic bowel resection
Intravenous ipamorelin (0.03 mg/kg twice daily) did not significantly shorten time to recovery of bowel function versus placebo; it was well tolerated, and the program was later discontinued for commercial reasons.
Trial identifier needs verification
Storage & handling
- Lyophilized
- Refrigerate the lyophilized powder at 2–8 °C, protected from light; brief room-temperature shipping excursions are generally tolerated.
- Reconstituted
- After reconstitution, refrigerate at 2–8 °C and use within ~4 weeks. Do not freeze.
Comparisons
| Vs. | Target | Half-life | Dosing | Efficacy | Status |
|---|---|---|---|---|---|
| GHRP-6 | Ghrelin/GHS-R (both) | ~2 h vs ~15–60 min | 1–3× daily (both) | Comparable GH pulse but far less hunger/cortisol than GHRP-6 | Both research-only |
| CJC-1295 (no-DAC) | Ghrelin vs GHRH | ~2 h vs ~30 min | 1–3× daily (both) | Complementary pathways — commonly stacked for additive pulses | Both research-only |
| Sermorelin | Ghrelin vs GHRH | ~2 h vs ~10–20 min | Daily (both) | Different receptor; often combined with GHRH-class peptides | Research-only vs formerly approved (withdrawn) |
Featured in these stacks
CJC-1295 (no-DAC) + Ipamorelin
This is the classic growth-hormone-secretagogue pairing. CJC-1295 without DAC (a GHRH analog, also called Mod GRF 1-29) increases the amount of GH released per pulse, while Ipamorelin (a selective ghrelin-receptor agonist) triggers a clean GH pulse with minimal effect on cortisol or prolactin.
Tesamorelin + Ipamorelin
This pairing follows the classic GH-secretagogue logic of combining a GHRH analog with a ghrelin-receptor (GHRP) agonist, but upgrades the GHRH side to tesamorelin — a stabilized GHRH analog that is the only growth-hormone-axis peptide in this category with FDA-approved human efficacy data, specifically for reducing visceral adipose tissue in HIV-associated lipodystrophy (marketed as Egrifta). The premise is that tesamorelin amplifies the size of each GH pulse at the pituitary while ipamorelin, a highly selective ghrelin-receptor agonist, both adds a second, independent pulse trigger and suppresses somatostatin, the brake on GH release.
Advanced Recomp (GH secretagogue + repair)
This is a body-recomposition construction that combines two goals in one protocol: amplifying the body's own growth-hormone output and supporting tissue recovery. The GH side uses the classic secretagogue pairing — CJC-1295 (no-DAC), a GHRH analog that increases the amount of GH released per pulse, plus ipamorelin, a selective ghrelin-receptor agonist that triggers a clean GH pulse without raising cortisol or prolactin. Acting on two different receptors, they amplify pulsatile GH and downstream IGF-1 more than either does alone.
Sources & references
- [1]Raun K et al. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol 1998;139(5):552-561. ↗ source
- [2]Beck DE et al. Evaluation of ipamorelin (a growth hormone secretagogue) for postoperative ileus. PubMed record. ↗ source
- [3]Gobburu JV et al. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a GH secretagogue, in healthy volunteers. J Clin Pharmacol 1999. ↗ source
Frequently asked questions
Why is ipamorelin considered 'cleaner' than GHRP-6?
In pharmacology studies ipamorelin releases growth hormone with little effect on cortisol, prolactin, or appetite, whereas GHRP-6 causes pronounced hunger and can raise cortisol. That selectivity is the main reason ipamorelin is the more popular ghrelin-class secretagogue.
Why combine ipamorelin with CJC-1295?
They act on two different receptors — ghrelin (GHS-R) for ipamorelin and GHRH for CJC-1295. Stimulating both pathways at once produces a larger combined GH pulse than either peptide does alone, which is the rationale behind the popular CJC-1295 + ipamorelin pairing.
Should it be taken away from food?
Community practice times ipamorelin away from meals — especially carbohydrate and fat — because elevated blood sugar and somatostatin can blunt the GH response. A common pattern is dosing fasted or before bed.
Related protocols
CJC-1295 (no-DAC)
Mod GRF 1-29
Short-acting GHRH analog dosed for natural GH pulses
GHRP-6
Growth Hormone Releasing Peptide-6
First-generation ghrelin-receptor agonist defined by its strong appetite stimulation
Sermorelin
GRF 1-29
GHRH(1-29) — the shortest fully active GHRH fragment, dosed nightly to reinforce the natural GH pulse
Looking to match this protocol to a verified research vial? Our partner supplier publishes a certificate of analysis per batch.
For educational and research reference only. Not intended for human consumption, not medical advice. Compounds discussed are sold and used for laboratory research purposes only.