Ive been taking ZzzQuil and other sleep aids for a while now, about two months ago i realized i had dry mouth. Mostly when i woke up in the morning, when i read online that sleeping pills can cause dry mouth, i immediately stopped taking them. still though, from time to time, i have dry mouth. Can side effects of sleeping pills last a long time? Ive gone to the doctor and he took my blood and said theres nothing wrong and every things working fine. Its just an annoying thing to have a dry, sticky mouth, and sometimes bad breath.