Hydrocodone is a semisynthetic opioid derived from codeine (or thebaine) through chemical modification in a lab, making it a distinct compound with a different structure. While closely related to codeine and morphine both opioids used for pain relief and cough suppression hydrocodone is generally stronger and more potent than codeine. Prescription products like Vicodin contain hydrocodone (often with acetaminophen), but never codeine itself. They are separate medications, though someone allergic to codeine may also react to hydrocodone due to their similarity