Prescription
Antihistamine (also used as anti-nausea and sedative)
Promethazine Hydrochloride
Last reviewed April 2026
Who is this for?
What is this drug?
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.
What is it used for?
Allergies (sneezingitchingwatery eyesskin rash)nausea and vomitingmotion sickness (travel sickness)difficulty sleepingcough and cold symptomsitchy skin
Prescription Required
A doctor's prescription is required to obtain this drug legally.