What Does a Heroin Overdose Look Like?

Which panels screen for it

The details that matter

Heroin is not itself a panel analyte. Within minutes of use it is deacetylated to 6-acetylmorphine (6-MAM) and then to morphine, so classic opiate strips catch the morphine metabolite — but a morphine positive alone cannot prove heroin, because codeine, morphine, and poppy seeds produce the same result.

6-MAM is the heroin-specific marker. No other drug, food, or medication produces it, which is why labs order a 6-MAM confirmation (typically ~10 ng/mL) when they need to prove heroin specifically. The catch: 6-MAM clears within roughly 8–22 hours, so it is only detectable for about a day after use.

Poppy seeds can never cause a 6-MAM positive. They contain morphine and codeine, not heroin, so a confirmed 6-MAM result is definitive evidence of heroin exposure regardless of what you ate.

Street heroin is frequently adulterated with fentanyl, which is far more potent and is itself screened on many expanded panels. A heroin user can therefore produce a fentanyl positive even if they never knowingly took fentanyl — and the overdose risk is the real danger.

If it IS detected, how long does it last?

False-positive notes

• Poppy seeds produce genuine morphine/codeine positives but never 6-MAM; the 2,000 ng/mL opiate cutoff is calibrated to tolerate dietary exposure.
• Codeine metabolizes to morphine in the body, so a morphine positive without 6-MAM is consistent with codeine, morphine, or heroin — 6-MAM confirmation is what separates them.

Remember: immunoassay screens produce artifacts; mass-spec confirmation and the MRO review are where legitimate explanations win.

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