are coffee and tea diuretics
Answer Wiki. Caffeine is a diuretic to begin with and it's not possible to remove 100% of caffeine from tea. Having said that though you need larger doses of caffeine (6-8 cups of non decaf tea) to have a diuretic effect, and even this is for people to that don't intake a lot of caffeine, as your body develops a tolerance to it.
This means that decaffeinated tea may still contain some caffeine. Having said that though you need larger doses of caffeine (6-8 cups of non decaf tea) to have a diuretic effect, and even this is for people to that don't intake a lot of caffeine, as your body develops a tolerance to it.