Ipamorelin

What it is

Ipamorelin is a lab-made chain of 5 amino acids (Aib-His-D-2-Nal-D-Phe-Lys-NH2) developed by Novo Nordisk scientists and first described in 1998. It works by binding the ghrelin receptor (GHS-R1a) in the pituitary gland - the same receptor targeted by older growth-hormone-releasing peptides (GHRPs) such as GHRP-6 and GHRP-2. What set ipamorelin apart in that original study was selectivity: in swine, it released growth hormone about as strongly as GHRP-6, but unlike GHRP-6 or GHRP-2, it did not meaningfully raise cortisol, ACTH, prolactin, FSH, LH, or TSH, even at doses 200 times higher than what was needed for GH release. That is the basis for describing it as a cleaner GH pulse than older GHRPs. There is real human data too: a 1999 dose-escalation study gave IV ipamorelin to 40 healthy men and found a short plasma half-life of about 2 hours, with a single, brief pulse of GH release peaking roughly 40 minutes after dosing rather than a sustained rise. What has not been studied in a published human trial is the kind of daily subcutaneous self-injection protocol used in wellness and bodybuilding circles - the microgram doses, the pairing with CJC-1295, and the reconstitution recipes all come from vendor guides and community reporting, not from a clinical dosing trial.

Dose ranges

Study-backed ranges carry a source you can open. Community ranges are widely reported but not clinically established - treat them as what people do, not as advice.

Reconstitution & storage

Vendor/community convention, not a manufacturer standard - no FDA-approved ipamorelin product exists. The most commonly cited combination is a 5 mg vial with 2 mL bacteriostatic water, giving 2.5 mg/mL (2500 mcg/mL), which lines up with clean insulin-syringe units (200 mcg = 8 units, 300 mcg = 12 units). 2 mg vials and larger 10 mg vials (common in pre-blended CJC-1295/ipamorelin products) are also sold; BAC water volume is generally scaled to keep a similar concentration. Guides consistently say to inject the water slowly down the inside wall of the vial and swirl gently rather than shake.

Common stacks

Interactions & cautions

No formal human drug-interaction studies exist for ipamorelin. The one relevant mechanistic finding comes from a 2004 rat study: ipamorelin directly stimulated insulin release from pancreatic tissue in both normal and diabetic rats, acting through calcium-channel and adrenergic-receptor pathways. Separately, growth hormone itself is counter-regulatory to insulin and can transiently reduce insulin sensitivity - a well-established effect of the GH axis in general, not something proven for ipamorelin specifically at self-injection doses. Together these are reasons for caution rather than proof of a clinical interaction: anyone with diabetes or insulin resistance should not self-dose without medical supervision. Community guides also report dose-dependent water retention, injection-site flushing, and mild headache, most often in the first one to two weeks of use. As with any GH secretagogue, there is a theoretical caution around active cancer or a cancer history (GH/IGF-1 signaling can support tumor growth) and around pregnancy or breastfeeding, since neither has been studied. Ipamorelin is not FDA-approved and carries no official drug label, so there is no authoritative interaction list to check against - everything above is mechanism-based or community-reported, not clinical.

Questions people ask

Sources

1. [1]Ipamorelin, the first selective growth hormone secretagogue PMID 9849822studyOriginal 1998 characterization: in conscious swine, ipamorelin released GH (ED50 2.3 nmol/kg) with potency similar to GHRP-6, but unlike GHRP-6 or GHRP-2 it did not raise ACTH or cortisol even at doses 200-fold above the GH-release ED50, and none of the secretagogues tested affected FSH, LH, prolactin, or TSH.
2. [2]Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers PMID 10496658studyIn 40 healthy male volunteers given IV ipamorelin (4.21-140.45 nmol/kg), pharmacokinetics were dose-proportional with a terminal half-life of about 2 hours, clearance of 0.078 L/h/kg, and steady-state volume of distribution of 0.22 L/kg; GH release was a single pulse peaking at 0.67 hours post-dose.
3. [3]Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption PMID 9879640studyIn rats, IV ipamorelin had systemic plasma clearance about 5-fold lower than GHRP-6; estimated intranasal bioavailability was approximately 20%, versus roughly 50% for several comparator secretagogues.
4. [4]Mechanism of ipamorelin-evoked insulin release from the pancreas of normal and diabetic rats PMID 15665799studyIpamorelin significantly increased insulin secretion from pancreatic tissue of both normal and diabetic rats in vitro, acting through calcium-channel and adrenergic-receptor pathways - the mechanistic basis for a blood-sugar caution.
5. [5]Tesamorelin + Ipamorelin / CJC-1295 GH-Pulse Stack Dosing Guide (community guide)communityCommunity protocol guide reporting typical reconstitution (5 mg/5 mg blend plus 2 mL bacteriostatic water = 2.5 mg/mL each) and self-dosing of 100-300 mcg of each peptide once daily, titrated up over about 12 weeks; explicitly labels these as research-planning ranges, not clinical dosing.
6. [6]Ipamorelin Reconstitution Guide (community guide)communityCommunity reconstitution and storage guide: 2 mg and 5 mg are the standard vial sizes, 2 mL bacteriostatic water per 5 mg is the most-cited dilution, and reconstituted solution is commonly stored refrigerated for up to 28 days; states its sourcing is published research plus self-reported community sources, not medical advice.
7. [7]Ipamorelin Side Effects: What to Expect, What's Rare & How to Minimize Them (community guide)communityCommunity side-effect guide reporting common self-reported effects: brief post-injection flushing, mild headache in the first 1-2 weeks, dose-dependent water retention at 300 mcg and above, and nausea or lightheadedness linked to low blood sugar if injecting after fasting too long.