In one of my recent blogs, I wrote coffee could dehydrate you. Yes, caffeine dries out your skin, not only dehydration, but also gives you headaches, and cause noxious feeling after drinking it. Agree? No, wrong. After a quick research, I discovered that caffeine doesn't dehydrate you!
Coffee, or the caffeine in coffee does cause your kidney to flush extra water through urination which the stimulant is very mild. So, drinking a bunch of caffeinated drinks may have you use the restroom more frequently, technically dehydrating, however, it isn't enough to have an impact on your body's water volume. Also, because you are ingesting that caffeine with a volume of fluid, you're balancing any liquid lost through urination.
Of course, not everyone will feel great after a venti latte. Some may be just sensitive to caffeine which triggers headaches, but with the studies, it's unlikely to get dehydrated with the consumption of caffeine.