Antihistamine (also used as anti-nausea and sedative)
Last reviewed April 2026
Who is this for?
Promethazine is an antihistamine that works by blocking a natural substance called histamine in your body. It helps reduce allergic reactions, prevents nausea and vomiting, and can make you feel sleepy, which is why it is sometimes used to help with sleep or calm you down before surgery.
Prescription Required
You need a doctor's prescription to buy this drug.
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