[bitL]

I don't know frankly. I was surprised it was so easy for me, but let's say first day I get headaches which I attribute to caffeine/sugar withdrawal, maybe that's your case as well. Drinking 1 liter of water quickly often resolves that though. It's possible you are actually dehydrated as most water comes from food and not drinks, so if you continue drinking like you are used to, you end up with insufficient water.

[sizzle]

Just drinking water can lead to electrolyte imbalance or is am I mistaken?

[bitL]

You are completely right. If you scroll up 3 posts you'll see I mentioned "electrolytes-only".