The original brand-name product, Desyrel, is no longer marketed, and trazodone is available today exclusively as a generic medication, manufactured by multiple pharmaceutical companies. FDA generic approval requires bioequivalence — meaning the generic must deliver the same active ingredient to the bloodstream at a comparable rate and extent as the reference product did.
In practice, this means whichever manufacturer's tablets your pharmacy stocks should work the same way for you, though inactive ingredients (fillers, dyes) can differ slightly between manufacturers, which occasionally matters for people with specific allergies or sensitivities.