Think of it like all those commercials for different medications they have on TV, where listing the potentially fatal side effects takes nearly three minutes. Potions are like that, except now you're using bits of mystical flora as well as modern chemistry. Drinking them will always kill you--the difference between a good potion maker and a bad one is getting them to do it softly.

For young vamps death isn't much of a deterrent, so they oftentimes get hooked early and have to deal with the increasingly torturous wraithburn of their decision.