HGH (somatropin) is FDA-approved for 10+ specific conditions — not anti-aging or bodybuilding, which is a federal felony under US law. This 2026 guide covers all approved indications, genuine adult GHD symptoms and diagnosis, the IGF-1 mechanism, an 8-brand HGH comparison table, long-acting GH (Sogroya) update, and what research actually shows about HGH in healthy adults.