Somapacitan vs Somatropin (rhGH)
A once-a-week growth hormone shot that replaces daily shots. Controlled trials show it works as well as daily doses. It is lab-made growth hormone, approved for children and adults who lack it. It works for that, but anti-ageing clinics also sell it to healthy adults, and the labels do not back that.
Both sit at grade A: strong human evidence. Both are FDA approved.
Evidence
AStrong human evidence
AStrong human evidence
Human studies cited
Animal or cell studies cited
Why the grade
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.
The approved indications rest on four decades of randomized and controlled trials summarized in each product's label, including placebo-controlled trials in adult deficiency and growth velocity trials in children; the Norditropin label alone covers pediatric and adult deficiency, Turner syndrome, Noonan syndrome, Prader-Willi syndrome, small-for-gestational-age short stature and idiopathic short stature. Evidence for the uses it is sold for off-label, anti-aging and body composition in healthy adults, is a separate and much weaker question not covered by these citations.
FDA
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.
FDA approved
Somatropin, recombinant human growth hormone, has been FDA-approved since Humatrope in 1987 and is sold under several brands including Norditropin, Genotropin, Omnitrope and Zomacton, for growth hormone deficiency in children and adults and for a set of specific growth disorders. Two long-standing brands have left the market: Genentech discontinued Nutropin in 2024 and Lilly is ending Humatrope distribution at the end of 2026. Use for anti-aging or athletic performance is not an approved indication.
Sold for
Somapacitan is the once-a-week growth hormone that replaces daily injections for children and adults who lack the hormone.
Growth hormone is sold by anti-aging clinics and on the black market as the master hormone for youth, muscle and fat loss, well beyond the deficiency states it is approved to treat.
Studies say
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.
Somatropin reliably restores growth in children who lack growth hormone and improves body composition in deficient adults, which is what it is approved for; the labels do not support use in healthy adults, and the market is shifting toward weekly long-acting versions as older daily brands exit.
Class
Long-acting GH analog
Growth hormone
Route
Injection
Injection