I may have accidentally ingested marijuana through a brownie. how long will the dry mouth last?

4-8 hours: When marijuana is smoked the effects last 1-4 hours. When ingested it takes 30-120 minutes to feel and then lasts 3-7 hours once you start feeling it (partly depending on dose). If you fall asleep the effects should dissipate by the time you wake up. Drink water to help with dry mouth symptoms. Relax and try listening to music. See http://www.Erowid.Org/plants/cannabis/cannabis_effects.Shtml.