The primary active ingredient in Fish Mox 250mg is **amoxicillin trihydrate**. * Colloidal silicon dioxide (dis * Sodium lauryl sulfate ( **Please note:** This product is formulated for ornamental aquarium fish only and is not for human consumption. Individuals allergic to penicillin should handle it with care. For specific medical or aquarium-related advice, please consult an aquatic veterinarian.