Replying to @ShitpostGatejust checked the LD50, ie the amount that has a 50% chance to kill a person and it's 150 to 200 mg per kilogram
at 150lb, he's 68kg. lower end, he needs 150mg x 68 = 10,200 mg.
if we just take it as linear 10,200/1,080 = 9.5% chance he dies