A quick answer: Heroin is generally detectable in urine for 1–3 days (the unique marker 6-MAM clears in ~2–8 hours). Blood, saliva, and hair have different windows — and several personal factors change the timeline. Here is what the science says, and how to confirm a result definitively. (Also searched as: 6-MAM, diacetylmorphine, smack.)
Heroin detection windows
Typical detection windows by test type:
| Urine | 1–3 days (the unique marker 6-MAM clears in ~2–8 hours) |
|---|---|
| Blood | up to 6 hours |
| Saliva | up to ~1 day |
| Hair | up to 90 days |
Detection windows are general estimates and vary by dose, frequency of use, individual metabolism, body composition, hydration, and the test’s cutoff level. They are not guarantees or medical advice. Hair testing generally reflects roughly the prior 90 days for all substances.
What affects how long Heroin stays in your system
Heroin breaks down quickly into 6-acetylmorphine and then morphine; the 6-MAM marker confirms heroin specifically but has a very short window. In general, higher doses, more frequent use, slower metabolism, and higher cutoff sensitivity all lengthen how long a substance is detectable. There is no reliable way to "flush" a substance out faster than your body clears it.
Test for Heroin
To confirm Heroin definitively, use a lab-confirmed test. Order a private at-home drug test (the 12-panel covers Heroin (as 6-MAM)), or set up employer testing. Every LabX positive is confirmed by LC-MS/MS.
Order an at-home test → For employers
Talk to a licensed physician
The detection times on this page are general estimates, not medical advice. If you have questions about a substance, a medication or your health, talk to a licensed physician. In an emergency call 911, or Poison Control at 1-800-222-1222. See our medical disclaimer.