If the activated charcoal works or not, I don't know... I've been taking it from time to time, in small doses, and quite frankly I haven't noticed much of a difference. But with that being said, charcoal-tinted ice cream and candy and smoothies makes for excellent Instagram pictures so I will keep using it just for fun. Black-hued dishes are rare and unique — and lets be honest, doesn't it look really cool?! :P
Coolness aside: I recommend buying high quality and Pure Activated Coconut Charcoal. Everyone responds differently to different doses, so to avoid potential undesirable effects, such as constipation, please consult your doctor and use only as suggested.
Never take activated charcoal with prescription medications! Excessive charcoal consumption, can result in constipation.
Final warning, if you use activated charcoal, it will stain your poop black. This is great because it tells you how long food takes to go through your bowel (called transit time). So don't be scared! :P