Ipamorelin
NNC 26-0161
The most selective GH secretagogue — a clean pulse of growth hormone with minimal off-target signalling.
Class
Ghrelin receptor (GHS-R) agonist / GH secretagogue
Half-life
~2 hours
Evidence
Animal models
Animal models
Evidence comes primarily from rodent or other animal studies. Translation to humans is unproven.
Overview
Ipamorelin is a pentapeptide that mimics ghrelin at the growth-hormone-secretagogue receptor, prompting the pituitary to release a pulse of your own growth hormone. Its defining trait is selectivity: unlike older secretagogues, it raises GH with essentially no increase in cortisol, prolactin, or ACTH at typical doses.
Because it stimulates endogenous GH release rather than supplying exogenous hormone, the pituitary's own feedback loops stay intact — you get a physiological pulse rather than the flat, supraphysiological levels that injected rhGH produces. This is why it is almost always paired with a GHRH analogue like CJC-1295, which amplifies the amplitude of each pulse.
Human data is thin — most evidence is preclinical or from related secretagogues — so effects on body composition and recovery are inferred rather than proven in controlled human trials. It is not approved for human use.
How it works
- Binds the GHS-R1a receptor on pituitary somatotrophs, triggering GH release.
- Highly selective — minimal cortisol, prolactin, or ACTH elevation, distinguishing it from GHRP-6 and hexarelin.
- Preserves pulsatile GH secretion and negative feedback, unlike exogenous rhGH.
- Synergistic with GHRH analogues: the secretagogue increases pulse frequency while GHRH increases pulse amplitude.
What the research shows
Researched effects
- Increased GH and downstream IGF-1 in animal and limited human pharmacology studies
- Anecdotal improvements in recovery, sleep quality, and body composition
- Does not meaningfully raise cortisol or prolactin at standard doses
- May improve gastric motility via the ghrelin pathway
Limitations & what it won't do
- No large controlled human efficacy trials for body composition or recovery.
- Effects are modest and gradual — not comparable to exogenous GH or anabolic steroids.
- Benefits depend heavily on sleep, training, and nutrition being in order first.
- Not FDA approved for any indication.
Dosing protocols
These ranges reflect published trials and community protocols. They are reference information, not a prescription. Doses are per injection unless noted.
Standard secretagogue protocol
100–300 mcgCommonly combined 1:1 with CJC-1295 (no DAC). A pre-bed dose leverages the natural overnight GH pulse.
Saturation dose
~1 mcg/kg body weightDoses beyond receptor saturation add side effects without adding GH release.
Reconstitution & measuring your dose
Handling
- Typical vial sizes
- 2 · 5 · 10 mg
- Suggested BAC water
- 2 mL
- Storage
- Lyophilised powder refrigerated at 2–8 °C, protected from light.
- After reconstitution
- Reconstituted: approximately 30 days refrigerated. Do not freeze.
Why 2 mL? A 5 mg vial in 2 mL yields 2500 mcg/mL — 100 mcg lands on 4 units, 250 mcg on 10 units of a U-100 syringe.
Dose calculator
Draw to
4units
= 0.04 mL · 25 mcg per unit
Concentration
2500 mcg/mL
Doses per vial
50
Side effects
Common
- Transient head rush or flushing after injection
- Mild water retention
- Increased hunger (ghrelin pathway)
- Injection-site irritation
- Vivid dreams with pre-bed dosing
Serious / rare
- Elevated fasting glucose / reduced insulin sensitivity with prolonged high-dose use
- Theoretical stimulation of pre-existing tumours via IGF-1
Contraindications & interactions
Do not use if you have
- Active cancer or current oncology treatment
GH secretagogues raise IGF-1, which can promote proliferation of existing malignancies. Active cancer is an absolute contraindication.
- Pregnant, breastfeeding, or trying to conceive
No pregnancy safety data.
Use caution if you have
- Type 2 diabetes or insulin resistance
GH pulses can transiently reduce insulin sensitivity and raise fasting glucose. Monitor closely.
- Type 1 diabetes
Glucose effects require careful insulin coordination.
- Past cancer diagnosis (in remission)
IGF-1 elevation in someone with a prior malignancy warrants oncology clearance.
- Carpal tunnel or nerve compression
GH-mediated fluid retention can aggravate nerve compression.
Medication interactions
- monitorInsulin — GH pulses oppose insulin action; glucose may run higher. Watch for dose adjustments.
- cautionGrowth hormone (rhGH) — Stacking a secretagogue on exogenous rhGH is redundant and pushes IGF-1 higher than intended.
- monitorCorticosteroids — Steroids blunt GH secretion, reducing secretagogue efficacy.
What to monitor
- Fasting glucose and HbA1c
- IGF-1 levels if available
- Blood pressure and fluid status
- Symptoms of carpal tunnel
Commonly combined with
References
- Raun K et al. — Ipamorelin, the first selective growth hormone secretagogueEuropean Journal of Endocrinology 1998;139:552-561
Research & educational information only — not medical advice.
You must be 18 or older to use this site. The peptides described are presented as research chemicals intended for research purposes only. Most are not approved by the FDA for human use. Dosing ranges reflect what has appeared in the scientific literature or community protocols and are not prescriptions. Nothing here replaces evaluation by a licensed physician who knows your full medical history.
Want to know if Ipamorelin fits your goals and history?
The assessment cross-checks your medical history and medications against this and every other compound before it recommends anything.
Start the assessment