[citation needed] Heroin is rapidly metabolized by esterase enzymes in the brain and has an extremely short half-life.

Therefore, heroin acts as a pro-drug, serving as a lipophilic transporter for the systemic delivery of morphine, which actively binds with μ-opioid receptors.

6-MAM can be synthesized from morphine using glacial acetic acid with an organic base as a catalyst.

This is significant because a urine immunoassay drug screen typically tests for morphine, which is a metabolite of a number of legal and illegal opiates/opioids such as codeine, morphine sulfate, and heroin.

[5] 6-MAM is naturally found in trace amounts in rat and cow brains.