|Nomenclature & Identifiers|
|Formula||C H O|
|Molar mass||g mol-1|
|Related compounds||Morphine, Oxycodone, Thebaine.|
Codeine, or methylmorphine is an opium alkaloid that occurs naturally in the sap of the papaver somniferum (opium poppy) plant. It acts as a prodrug for morphine (its active metabolite), with approximately 10% of codeine being metabolized into morphine in the liver. As a result of this codeine's activity is around 1/10th of the strength of morphine.