Glow (derived from "Glyco Lauric Octanol" and its glowing effect) is a street drug that appeared in Final Fight: Streetwise. At first it was rare and its details were sketchy, but officials feared that the spread of this drug could have dire effects on the city. True to their prediction, the drug spreads at an alarming rate and Glow Heads start a riot, causing chaos in Metro City.
The drug was created by Dr. Chang under Father Bella's orders to destroy the Metro City, its factory being hidden in the Pier District. Wearers of glow become stronger than normal and don't fell pain, but they become unstable, aggressive, and highly addicted to the drug. The eyes of glow users gain an eerie green glow, and their veins usually also glow green. Larger doses increase muscular mass. Father Bella and Dr. Chang also used glow to create powerful mutations known as the Four Horsemen of the Apocalypse.