I have a friend that swears by activated charcoal said she wouldn't ever be without it. She hikes all the time and tells me it will kill or absorb snake venom. But if I'm not mistaken she told me to drink plenty of water with it because it will very easily cause you to be constipated which would be great for the runs lol.
She has it in powder form and says its hard to swallow but she likes it better than the capsules for some reason. Great stuff to have around although I've never used it.