Which of the following is NOT a natural opiate?

Heroin is the correct answer because it is not classified as a natural opiate. Natural opiates are substances that are directly derived from the opium poppy plant. Opium is the raw material from which both codeine and morphine are extracted. These two compounds are naturally occurring alkaloids found in opium.

Heroin, on the other hand, is a semi-synthetic opioid. It is synthesized from morphine, which means it has undergone chemical modifications to enhance its potency and effectiveness as a drug. While heroin is related to natural opiates in terms of its origin from morphine, it does not occur in nature without human intervention, distinguishing it from the other substances listed. Understanding this classification is essential for recognizing the differences in how these substances interact with the body and their potential for addiction.