Being neither a chemist, nor a physician I haven't the faintest idea! But from my own researches, I don't see why it would be hard to do for someone who knew what he was doing. Assuming A and his cohorts aren't pressed for time, they can start gradually and adjust the concentration upwards if things aren't moving quickly enough or downwards if the physical side-effects become too pronounced. People can die, but that's not so likely if A and the others are on hand, watching. More likely are long term problems to health -- but I'm assuming that A isn't too bothered about that. And it gives you material for Book 3!