waterbug
I drank so much coffee and teas before I fasted that I didn't get much out of it, I could go to sleep after having coffee.The last time I water fasted for 10 days, I had some green tea and I really felt it's effects like never before, my body became so sensitive to caffeine. Another time I went 3 days on just coffee and tea, and I got sharp chest pains, so I started eating again. Dr. Joel Furhman who
Water Fasts people wrote that it is dangerous to doing "something like fasting" like drinking coffee and teas, I don't know about herbal teas but I would just stick to water to be on the safe side, but obviously you are free to do as you please.