Brown-brown is a purported form of cocaine or amphetamine insufflation mixed with smokeless gunpowder. This powder often contains nitroglycerin, a drug prescribed for heart conditions, which might cause vasodilation, permitting the cocaine or amphetamine insufflation to move more freely through the body. This, in turn, is believed to allow for a more intense high. The term may also refer to heroin.

Brown-brown is reportedly given to child soldiers in West African armed conflicts. One former child soldier, Michel Chikwanine, has written a graphic novel with Jessica Dee Humphreys called Child Soldier, about the experience of being captured at the age of 5 by rebel fighters in the Democratic Republic of Congo, including being given brown-brown. "The rebel soldier who had hit me used a long, jagged knife to cut my wrist and rubbed powder into the wound. They called it Brown Brown – a mixture of gunpowder and a drug called cocaine. Right away, I began to feel like my brain was trying to jump out of my head."