Pain Reducer, or Pain Killer, is is used to temporarily boost ones threshold for injury. Pain Reducers/Killers can come in pill form (the most common), injections (rare), suppositories (commonly mistaken for pills), a patch, and possibly others.
First edition GW: (Genetic Booster does not appear in this edition.)
Second edition GW: A 15 centimeter long disposable jet-spray tube, containing special pain reducing drugs. The user feels no pain for the next 4 hours and can sustain 1 additional Hit Point for each point of Constitution. When the drug wears off, the user loses the ability to sustain this extra damage. If, at that point, he has no Hit Points left, he is dead. There is a 60% chance that the drug will work on Humanoids and Mutated Animals.