Does tizanidine have sulfa in it?

No, tizanidine does not contain sulfa. Tizanidine is a muscle relaxant that works by blocking nerve impulses and is not related to sulfonamide antibiotics, which are often referred to as "sulfa" drugs. If you have a sulfa allergy, it is generally safe to use tizanidine, but it's always best to consult with a healthcare provider before starting any new medication.