The PA4 Pain Amplification Serum is a chemical based upon the same ones given to Spartans to enhance their senses. However this compound only acts temporarily, but much more effectively. With it a person can hear, see, smell, taste, and feel more than thirty times what a Spartan can. At 20 cc smell and taste begin to add to the effects, and the amount of pain a person feels is roughly thirty to forty times that of normal.