Would Drinking a Lot of Water Impact Propecia?

In a recent post (Propecia and Coffee) you mentioned that some people believe that the increase in urination from drinking coffee and/or alcohol might diminish the impact of Propecia.

I currently drink about 1 gallon of water a day and because of this I urinate a lot. Could this prevent me from seeing maximum results from Propecia? Should I drink less water?

With respect to the post you are referring to, I never stated I believe in the theory that urination will make Propecia less effective. People write about these things on the Internet and the speculations get propagated (as I have probably contributed). So no — I do not think drinking and increased urination contributes to less efficacy of Propecia. I wouldn’t worry about it.

But, isn’t drinking a gallon of water a day considered excessive? I’d be concerned with possible water intoxication or hyponatremia.