Trazodone is FDA-approved only for major depressive disorder. Its widespread use for insomnia — typically at doses far lower than those used for depression — is off-label, meaning it is legal and common but not something the FDA formally reviewed and approved for that specific indication.
Off-label use
Also called: Off-label prescribing
Prescribing an FDA-approved drug for a purpose, dose, or age group not specifically listed on its approved label. Using low-dose trazodone for insomnia is a well-known example.