Key takeaways
Doxylamine (Unisom SleepTabs) and Nyquil Cold and Flu are both over-the-counter medications, but they have several differences. Doxylamine is a single-ingredient antihistamine used primarily as a sleep aid to help you fall asleep by blocking histamine in the brain. In contrast, Nyquil Cold and Flu is a combination medication that includes acetaminophen (a pain reliever), dextromethorphan (a cough suppressant), and doxylamine (an antihistamine). Nyquil is used to relieve multiple cold and flu symptoms like cough, sore throat, and fever. While both medications contain doxylamine, Nyquil also addresses pain and cough, making it more versatile for cold and flu symptoms. Doxylamine is typically taken once nightly, whereas Nyquil Cold and Flu can be taken every 6 hours as needed. Both can cause sleepiness, but Nyquil's additional ingredients mean you need to be cautious about potential liver damage from acetaminophen and interactions with other medications.
