Starts with poppy-based raw material (codeine, morphine, thebaine) and chemically alter these in the lab to come up with hydromorphone, hydrocodone, oxycodone
, desomorphine, diacetylmorphine (heroin), etc.
Opioid, fully synthetic: Fentanyl, pethidine, methadone, tramadol, dextropropoxyphene, buprenorphine (suboxone), etc. Created in lab with no need for raw material derived from the poppy. Many derived from petroleum.