Looking online I see everything from 200mg to 2000mg per kg of body weight. It's closer to 200mg than 2000mg, most sources are under 400mg. Maybe like 200 pills or something if you want to be sort of safe? Or of course you can do a ton more. I mean you might be able to die with just 100 pills, who knows. Really, this is a pretty atypical way to die. I'd recomend another method. Also please note all the info I found was non-human, like rats and stuff.