Hi doctors! how many hours before i go to sleep would it be ok to drink regular keurig coffee and not have the caffeine adversely affect my sleep?

About 6 hours: Many people are affected by regular or decafinated coffee. I would consider drinking water rather than coffee. A herbal tea may be an alternative.

Depends on you: There is no easy way to answer this question. The half-life (time it takes to clear half the drug from your body) of caffeine is 6 hours. If you drink coffee all day the amount in your system stacks up but then you probably have a high tolerance. Truth is, some people sleep like babies on caffeine and others are wide awake all night from drinking a cup at noon. Regular use blunts the wakefulness.