Hydrocodone is an opioid medication used for treating pain. You can Buy Hydrocodone Online; it is sold under the brand name Hysingla ER. Hydrocodone is used to treat the pain severe enough for an opioid. Hydrocodone works in the brain and changes how your body responds to the pain. It consists of a non-opioid pain reliever, Acetaminophen, which increases the effect of Hydrocodone and reduces fever; Hydrocodone is taken orally.