Substance guides

How long does heroin stay in your system?

Published January 9, 2026 · 7 min read · Updated April 2026

Reviewed for accuracy by licensed clinical professionals.

Heroin has one of the shortest half-lives of any opioid at approximately 30 minutes, but its metabolites remain detectable much longer.

Detection by test type

Urine: 2-4 days. Heroin is rapidly metabolized to 6-MAM and then to morphine. Standard opioid panels detect morphine. Specialized testing for 6-MAM confirms heroin specifically. Blood: 6-12 hours. Saliva: 1-2 days. Hair: up to 90 days.

The fentanyl factor

Most street heroin now contains fentanyl, which has its own metabolite (norfentanyl) detected on separate fentanyl-specific panels, not standard opioid screens. If you test positive for both morphine and norfentanyl, it indicates heroin contaminated with fentanyl.

Treatment considerations

If you are considering buprenorphine (Suboxone) induction, the detection window matters for timing. Because fentanyl accumulates in fat tissue and releases slowly, many clinicians now use micro-dosing protocols for fentanyl-exposed patients.

Authoritative sources

This article references guidelines from: NIDA · SAMHSA · CDC

Frequently asked questions

How long does heroin stay in urine?

2-4 days. Urine tests detect morphine, heroin's metabolite. Specialized 6-MAM tests confirm heroin specifically.

Can drug tests tell heroin from prescription opioids?

Standard tests detect morphine from both sources. 6-MAM testing specifically confirms heroin use.

Does fentanyl in heroin show on the same test?

No. A separate fentanyl-specific panel is required to detect fentanyl and norfentanyl.

Disclaimer: Informational only. Not medical advice. SAMHSA: 1-800-662-4357.