Ipamorelin

Growth hormone axis

Also known as NNC 26-0161

A selective ghrelin receptor agonist, chosen for not raising cortisol or prolactin.

Read this first

The well-known selectivity claim, that it releases growth hormone without raising cortisol or prolactin, comes from a study in conscious swine. No dedicated human selectivity study was found. The longest human exposure on record is 7 days, by a different route and at roughly 10 to 20 times community doses.

How it works

A pentapeptide agonist at GHS-R1a. Its selling point over GHRP-6 and GHRP-2 is selectivity: in the original characterisation it released growth hormone without the accompanying ACTH, cortisol and prolactin rise.

Subcutaneous

In the body

Half-life

2 hours

Time to peak

30 min

90% gone after

6.6 h

Builds up to

1.02×

Steady state after about 10.1 h at one to three times daily.

Shape of a single dose, modelled as one compartment with first-order absorption. The peak is normalised to 100% because bioavailability and volume of distribution are not published for most of these compounds.

2 hours terminal, measured in humans. Clearance 0.078 L/h/kg, volume at steady state 0.22 L/kg. The growth hormone pulse it triggers peaks around 40 minutes, well before the peptide has cleared.

What happens, and when

0 min, 30 minGrowth hormone pulse rises and peaks.
30 min, 3 hPulse subsides. Peptide clearing.

Doses

100 mcg, 300 mcgone to three times dailyCommunity practice

Community convention, often paired with a GHRH analogue. No approved dosing exists.

Vial sizes

2 mg5 mg10 mg

Commonly treated as good for 28 days refrigerated once reconstituted.

Side effects

Headache, flushing, lightheadedness
Water retention and joint discomfort at higher doses
Less appetite stimulation than GHRP-6, though not none

Cautions

Active or suspected malignancy.
Diabetes or impaired glucose tolerance.

Status

Not approved. Its one substantial human trial, 0.03 mg/kg intravenously twice daily for 7 days in postoperative ileus, 117 patients, failed, and development stopped. Prohibited in sport at all times. Placed in FDA compounding Category 2 in September 2023.

Sources

Reference information for personal record-keeping. Not medical advice, and not a recommendation to use any of these compounds.