What it is
A long-acting growth hormone analog with a non-covalent albumin-binding side chain, administered as a once-weekly subcutaneous injection via prefilled pen.
How it works
Binds the growth hormone receptor and activates the same downstream JAK2/STAT5 pathway as endogenous GH. The albumin-binding side chain extends half-life and supports once-weekly dosing.
Where it's used
Used in adult and pediatric growth hormone deficiency as a less-frequent alternative to daily somatropin.
FDA-approved use
Replacement of endogenous growth hormone in adults and pediatric patients aged 2.5 years and older with growth hormone deficiency.
Reconstitution
Supplied as a pre-mixed solution in a prefilled pen; no reconstitution required.
Tracking it
Somapacitan is injectable, so two things matter in a log: when you dosed and where. Rotating sites and writing both down prevents the classic “did I already pin the left side?” problem. with a half-life of about 30 hours, a dose log also lets a tracker model the relative amount still in your system between doses.
Source
OpenFDA
Last reviewed 2026-06-11