Heavy Liquid is a five-issue limited series written by Paul Pope which has science fiction and cyberpunk elements.
[1] A former police officer known only as "S" operates as a private detective based in New York City, finding people and objects for a fee.
On its own, it is a metallic-liquid explosive, but it turns into "black milk" when cooked, and exhibits mind-altering, drug-like properties.
S then discovers from his pursuer that the Heavy Liquid is alien in origin, and may even possess some form of consciousness.
Ingesting the drug himself, S escapes by jumping onto another train, his physical abilities dramatically increased by the Heavy Liquid.