How long does theraflu stay in the system?

Theraflu typically contains ingredients like acetaminophen, diphenhydramine, and phenylephrine, which can vary in how long they stay in the system. Generally, acetaminophen has a half-life of about 2 to 3 hours, while diphenhydramine can remain effective for 4 to 6 hours. The effects of Theraflu may last for several hours, but the substances are usually eliminated from the body within 24 hours. However, individual factors such as metabolism and dosage can affect this duration.