Sleep aids: Not a magic cure

Most sleep aids available without a prescription contain antihistamines. Tolerance to the effects of antihistamines can develop quickly. The longer you take them, the less likely they are to make you sleepy.

In addition, these medicines can leave you feeling groggy and unwell the next day. This is the so-called hangover effect.

If you take other medicines, sleep aids may affect how those medicines work. Also, much is still unknown about the safety and effectiveness of sleep aids available without a prescription.