Long-acting GH analog · GH deficiency
A long-acting, lab-made version of human growth hormone. Its 191-amino-acid chain matches the natural hormone except for one swap, which lets a small side chain attach that grips the blood protein albumin so the drug lasts far longer. It is a prescription injection for growth hormone deficiency and several causes of short stature in children.
Growth hormone acts on GH receptors found on many tissues. Some of its effects are direct, and many are relayed through insulin-like growth factor 1 (IGF-1), which the liver makes in response. In children, this signaling drives growth at the open growth plates of the bones; in adults, it helps regulate body composition, including fat and lean mass. Standard growth hormone (somatropin) has to be injected frequently. Somapacitan carries an albumin-binding side chain attached at position 101. Binding to albumin is reversible: it shields the hormone from rapid clearance and lets it be released slowly, which is why it needs far fewer injections than somatropin. In trials, IGF-1 levels were used to guide treatment adjustments.
Evidence comes from randomized trials, mostly comparing it with standard somatropin. In REAL 1, 301 untreated adults with growth hormone deficiency received somapacitan, standard growth hormone or placebo; at 34 weeks somapacitan reduced truncal fat percentage compared with placebo and improved visceral fat and lean mass, and improvements were maintained with both somapacitan and standard growth hormone through 86 weeks2.
In REAL 4, 200 prepubertal children with growth hormone deficiency grew about 11.2 cm a year on somapacitan versus 11.7 cm on somatropin, meeting the trial's noninferiority goal, with similar adverse events3. In a 2026 phase 3 trial in 77 children with Noonan syndrome, growth was at least as fast as with standard somatropin and the authors reported it was faster4, though the FDA label describes growth in the two groups as similar1. Other arms of the same trial, in children born small for gestational age and with idiopathic short stature, support the 2026 label additions1.
FDA-approved as Sogroya (Novo Nordisk) in 2020 for adults with growth hormone deficiency, and in 2023 for children aged 2.5 and older with growth hormone deficiency. In 2026 the label added short stature in children born small for gestational age, Noonan syndrome and idiopathic short stature.
Per the FDA label, common effects in children include colds and other respiratory infections, ear infection, headache, fever, vomiting, diarrhea, limb pain and injection-site reactions; in adults, back and joint pain, indigestion, sleep problems, dizziness, swelling and high blood pressure. Warnings cover serious allergic reactions, tumor growth or recurrence, reduced insulin sensitivity, raised pressure inside the skull, fluid retention, adrenal and thyroid changes, hip and spine problems in growing children, and pancreatitis. It is not used in active cancer or acute critical illness.
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