Unisom is a brand name for doxylamine, which is an antihistamine medication used to treat occasional insomnia. It works by blocking certain natural substances in the body, such as histamine, which can cause drowsiness. Unisom is available in different forms, including tablets, gels, and melatonin gummies. It is a non-habit-forming medication that can help troubled sleepers fall asleep up to 33% faster and wake up feeling refreshed. Unisom should only be used for occasional sleeplessness, and if sleeplessness persists for more than two weeks, it is recommended to consult a doctor as it may be a symptom of serious underlying medical illness. Unisom is not expected to be harmful to an unborn baby, but it is recommended to consult a doctor before using it during pregnancy.