Ipamorelin
Not FDA-approved
Also known as: Aib-His-D-2-Nal-D-Phe-Lys-NH2
Ipamorelin is a lab-made peptide of five amino acids that triggers growth hormone release through the ghrelin receptor. In animal studies it did this without raising the stress hormone cortisol. In people, published clinical studies are limited to a dose study and one bowel-surgery trial, where it showed no benefit.
How it works
- It is a lab-made chain of five amino acids. Three are unusual building blocks: Aib, and the mirror-image (D) forms of naphthylalanine and phenylalanine.
- It activates the ghrelin receptor (GHSR-1a) in the pituitary gland, a different switch from the GHRH receptor. This releases growth hormone.
- In pig studies, it raised growth hormone without raising the stress hormones ACTH and cortisol, even at over 200 times the effective amount. Related peptides GHRP-2 and GHRP-6 raised both.
- In healthy men given it into a vein, it caused a single short burst of growth hormone.
Evidence
Body composition (muscle and fat)
No trial has tested ipamorelin's effect on muscle or fat in people. The only support is indirect: animal studies show that it releases growth hormone.
Bowel recovery after surgery (ileus)
In a trial of 117 adults after bowel surgery, it was no better than placebo at shortening the time to a first solid meal. It was well tolerated.
Caveats
- A second, larger bowel-surgery trial was completed in 2014, but no results have been posted.
- Published clinical data are limited to the week-long bowel-surgery trial and a single-infusion study in 40 healthy men. No study has followed people taking it for months.
- There are no safety rules specific to ipamorelin. By extension from other growth-hormone-raising drugs, it is generally avoided with active cancer and in pregnancy.
References
This page is for education only. It is not medical advice. Decisions about any treatment belong with a physician who knows your history.