Ipamorelin vs Somapacitan
Sold for anti-aging, fat loss and muscle. It does raise growth hormone in people, but the one outcome trial, in 117 bowel surgery patients, did not work. A once-a-week growth hormone shot that replaces daily shots. Controlled trials show it works as well as daily doses.
Somapacitan has the stronger evidence, grade A (strong human evidence) against grade C for Ipamorelin. Ipamorelin: Not approved. Somapacitan: FDA approved.
Evidence
CAnimal and cell studies
AStrong human evidence
Human studies cited
Animal or cell studies cited
Why the grade
For the anti-aging and body-composition use ipamorelin is sold for, no human trial exists. The human data are a 40-volunteer dose-escalation pharmacokinetic study showing a single growth hormone pulse, a 114-patient randomised phase 2 trial in post-operative ileus that found no benefit, and a comparative hormone study of related peptides. The selectivity claim comes from rats and swine.
The adult approval rested on REAL 1, a randomized, double-blind, placebo-controlled and active-controlled trial of 301 adults with growth hormone deficiency, and the pediatric approvals on randomized trials against daily somatropin, the most recent being the REAL8 basket trial across three indications. The question these trials answer is whether weekly somapacitan matches daily growth hormone, and they show it does.
FDA
Not approved
Ipamorelin is not approved by the FDA for any use and is sold online as a research chemical; its development for post-operative ileus was abandoned after a negative phase 2 trial. In 2023 the FDA placed it in Category 2 of its compounding lists, the category for substances with significant safety risks, and it remains there for outsourcing facilities (503B) although the nominations for pharmacy compounding (503A) were withdrawn in 2024. In October 2024 the Pharmacy Compounding Advisory Committee voted 12 to 0, with one abstention, against adding it to the 503A bulks list.
FDA approved
Somapacitan is FDA-approved as Sogroya (Novo Nordisk), a once-weekly injection, for adults with growth hormone deficiency (August 2020), children aged 2.5 and older with growth hormone deficiency (2023), and, since February 27, 2026, children aged 2.5 and older with idiopathic short stature, short stature after being born small for gestational age, or growth failure from Noonan syndrome.
Sold for
Ipamorelin is sold as the cleanest growth hormone secretagogue, for anti-aging, fat loss and muscle, usually paired with CJC-1295.
Somapacitan is the once-a-week growth hormone that replaces daily injections for children and adults who lack the hormone.
Studies say
Ipamorelin releases growth hormone in humans without the cortisol rise seen with GHRP-2 and GHRP-6, but the only outcome trial, in bowel surgery patients, was negative, and no study has measured body composition or aging, so the grade is C.
Randomized trials show weekly somapacitan reduces body fat in adults with growth hormone deficiency as well as daily growth hormone does and produces equivalent growth in children, which supports an A for its approved uses.
Class
GHRP / ghrelin receptor agonist
Long-acting GH analog
Route
Injection
Injection