Trazodone's elimination half-life is generally cited in the range of about 5 to 9 hours in adults, though individual results vary with age, liver function, and other factors. This relatively short half-life (compared with some other psychiatric medications measured in days) is part of why its sedating effect is most noticeable within several hours of a dose rather than lingering for days.
Complete elimination from the body takes roughly 5 half-lives, so trazodone is largely cleared within about 1 to 2 days after the last dose for most people — relevant context for interaction timing questions, though it doesn't change medical advice about tapering, which is based on avoiding withdrawal symptoms rather than pharmacokinetic clearance alone.