Ipamorelin
NNC 26-0161 · Ipam
The selective GHRP: a clean GH pulse with almost no cortisol, prolactin or hunger.
Typical dose
300 mcg
1-3x daily
Range
100–400
mcg
Half-life
2 h
see Dosing
Evidence
Early human
Subcutaneous · Intramuscular
What it is
Ipamorelin is a synthetic pentapeptide agonist at the ghrelin receptor (GHS-R1a), developed by Novo Nordisk in the 1990s. It was the first growth hormone secretagogue selective enough to raise GH without dragging ACTH, cortisol and prolactin up with it, which is why it displaced GHRP-6 and GHRP-2 as the default GHRP for most users.
The trade-off is potency. Ipamorelin releases less GH per microgram than hexarelin or GHRP-2, and it is normally run alongside a GHRH analogue, with CJC-1295 without DAC (mod GRF 1-29) the standard partner. A GHRP and a GHRH together produce a larger pulse than either alone.
Human data is thin: a phase 1 PK/PD study in healthy men and a phase 2 trial in postoperative ileus that failed its endpoint. Novo Nordisk shelved it and everything since has been research-chemical supply. Expect modest, slow effects. Sleep quality, recovery and a gradual shift in body composition over months, not weeks.
How it works
Ipamorelin binds GHS-R1a on pituitary somatotrophs and in the hypothalamus, mimicking ghrelin. It triggers GH release directly and also suppresses somatostatin, the brake that normally holds GH back. The result is a single discrete GH pulse peaking around 40 minutes after injection and clearing within a couple of hours.
Because it does not meaningfully activate the corticotroph and lactotroph pathways, and only weakly stimulates appetite, you get the GH pulse without the endocrine noise. Paired with a GHRH analogue the two mechanisms multiply: the GHRH raises how much GH the pituitary is willing to release, while the GHRP lifts the somatostatin brake.
Dosing
Past roughly 300 mcg per injection the size of the releasable pituitary pool, not the dose, is the limit. More frequent pulses beat larger ones.
Reconstitution calculator
Pre-loaded with Ipamorelin’s vial size, water volume and typical dose. Change anything.
Typical: 300 mcg · range 100–400
Draw to
12 u
0.12 mL · 300 mcg
Concentration
2.5 mg/mL
25 mcg per unit
Doses per vial
16.7
Vial lasts
8 days
Draw to 12 units on the barrel.
Once mixed
Refrigerate at 2-8 C, keep it out of light, and use within 3-4 weeks. Do not freeze a made-up vial.
Aim the bacteriostatic water down the inside wall of the vial rather than straight onto the powder, then swirl until clear. Do not shake. A 5 mg vial in 2 mL gives 2,500 mcg/mL, so a 300 mcg dose is 12 units on a standard 100-unit insulin syringe.
Storage
Before mixing
Sealed and dry it holds for months at 2-8 C and for years at -20 C; brief room-temperature transit does not ruin it.
After mixing
Refrigerate at 2-8 C, keep it out of light, and use within 3-4 weeks. Do not freeze a made-up vial.
Reported benefits
- ▪Raises GH without meaningfully raising cortisol, ACTH or prolactin
- ▪Almost no appetite spike, unlike GHRP-6
- ▪Desensitises slowly, so it tolerates long runs better than hexarelin
- ▪Deeper, more consolidated sleep is the most consistently reported effect
- ▪Supra-additive GH release when stacked with a GHRH analogue
- ▪Gradual gains in recovery, skin quality and connective tissue over months
Side effects
- ▪Head rush, warmth or brief lightheadedness in the first minutes after injecting
- ▪Water retention, puffy hands and morning stiffness
- ▪Carpal tunnel symptoms, tingling or numb fingers, at higher doses
- ▪Mild hunger for 20-30 minutes after a dose
- ▪Injection-site redness or a short-lived welt
- ▪Reduced insulin sensitivity and higher fasting glucose on long, high-dose runs
Do not use if
- ▪Active or suspected cancer, since GH and IGF-1 are growth signals
- ▪Poorly controlled diabetes or established insulin resistance
- ▪Active diabetic retinopathy
- ▪Untreated pituitary or hypothalamic disease
- ▪Pregnancy and breastfeeding
Evidence level — Early human
Small or early-phase human studies only.
Not approved by any regulator for human use, sold as a research chemical, and prohibited by WADA at all times.
Commonly run with
CJC-1295 no-DAC
Short-acting GHRH fragment that sharpens one GH pulse, almost always run with a GHRP.
100 mcg · 1-3x daily
CJC-1295 with DAC
Albumin-binding GHRH analogue that lifts GH and IGF-1 for days from one injection.
1000 mcg · 1-2x weekly
Sermorelin
The first 29 amino acids of human GHRH, once approved as Geref and now compounded.
300 mcg · once nightly, 5-7 nights per week
Tesamorelin
The only FDA-approved GHRH analogue, proven to shrink visceral abdominal fat.
2 mg · once daily
Ipamorelin FAQ
Ipamorelin or GHRP-2?+
GHRP-2 releases more GH per microgram, ipamorelin releases it cleaner. If you are dosing pre-bed, running long, or already prone to water retention and prolactin problems, ipamorelin is the safer pick. For maximum pulse amplitude over a short block, GHRP-2 wins.
Do I really have to be fasted?+
Carbohydrate, and to a lesser extent fat, blunts the GH response through insulin and free fatty acid feedback. Aim for two hours clear before the shot and 20-30 minutes clear after. In practice the pre-bed dose is the easiest one to keep genuinely fasted.
Why stack it with CJC-1295 no-DAC?+
They pull different levers. The GHRH analogue tells the pituitary to release more GH, ipamorelin lifts the somatostatin brake that limits the pulse. Together the release is larger than adding the two effects separately, which is why GHRP plus GHRH is the standard protocol.
Will it show up on a drug test?+
Yes. GHRPs including ipamorelin sit on the WADA prohibited list at all times, and urinary metabolite assays covering ipamorelin have been routine in accredited labs since the early 2010s. Detection windows are short but the tests exist.
How long before I notice anything?+
Sleep usually changes within the first week. Skin, joints and recovery take four to eight weeks. Body composition shifts slowly over months and the effect is modest. This is not a substitute for exogenous HGH and it will not feel like one.
References
- 1.Ipamorelin, the first selective growth hormone secretagogue — European Journal of Endocrinology (1998) PMID 9849822
- 2.Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers — Pharmaceutical Research (1999) PMID 10496658
- 3.Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients — International Journal of Colorectal Disease (2014) PMID 25331030
More gh secretagogues
CJC-1295 no-DAC
Short-acting GHRH fragment that sharpens one GH pulse, almost always run with a GHRP.
100 mcg · 1-3x daily
CJC-1295 with DAC
Albumin-binding GHRH analogue that lifts GH and IGF-1 for days from one injection.
1000 mcg · 1-2x weekly
GHRP-2
Potent, well-studied GHRP with a bigger pulse than ipamorelin and more cortisol.
100 mcg · 2-3x daily
GHRP-6
The original GHRP: solid GH release and the strongest hunger response of the group.
100 mcg · 2-3x daily