How long does heroin stay in your system?
One to two hours in blood, one to three days in urine, 90 days in hair. The half-life is about thirty minutes, which explains both the redosing and how fast withdrawal arrives.
Two Georgia locations
Woodstock, GA 30188
Hiram, GA 30141
Saturday–Sunday 9:00 AM – 12:00 PM
Heroin is detectable in blood for only 1 to 2 hours, in urine for 24 to 72 hours, and in hair for up to 90 days. Saliva windows are very short. Heroin has an unusually short half-life of about 30 minutes, and tests generally detect morphine, its main metabolite, rather than heroin itself.
By test type
Heroin detection windows
| Test | Detection window | Notes |
|---|---|---|
| Urine | 24–72 hours | Most common; confirmatory GC-MS extends the window |
| Blood | 1–2 hours | Rarely practical outside emergency or forensic use |
| Saliva | Under an hour to a few hours | Seldom used for heroin |
| Hair | Up to 90 days | Historical record of use |
Thirty minutes
The shortest half-life on this site
Heroin's half-life is roughly 30 minutes. Half the drug is gone from your system in the time it takes to drive across town.
Two consequences follow. First, people redose repeatedly through a day to hold the effect, which accelerates tolerance and dependence far faster than with longer-acting opioids. Second, withdrawal starts quickly — typically 6 to 12 hours after the last dose, peaking within 24 to 72 hours.
Tests do not generally look for heroin itself. It converts to morphine almost immediately, and morphine is what shows up on a panel — which is also why heroin registers on standard opioid screens while fentanyl does not.
What is sold as heroin frequently is not
Fentanyl has become widespread in the illicit opioid supply. That changes detection — standard panels catch heroin and miss fentanyl — and it changes treatment, because fentanyl stores in tissue and requires much more careful buprenorphine induction timing.
If you do not know what has actually been in your supply, say so at assessment. It is common, nobody reacts badly, and it materially changes the protocol.
After detox
The part that actually kills people
Heroin withdrawal is intensely unpleasant and almost never fatal. What is fatal is the return afterward.
A week without opioids drops tolerance dramatically. A dose that was routine last month can stop your breathing. Most opioid deaths following a period of abstinence — after detox, after jail, after a hospital stay — happen exactly this way.
Keep naloxone at home and make sure the people you live with know where it is. And finish detox with a plan rather than a handshake: see medication-assisted treatment, which roughly halves mortality risk for opioid use disorder.
Getting help
Withdrawal starts within twelve hours. It does not have to be done alone.
Buprenorphine, comfort medication and monitoring at our Woodstock and Hiram clinics, with appointments to 7:00 PM.
Common questions
Heroin detection, answered
How long does heroin stay in urine?
Roughly 24 to 72 hours. Basic immunoassays may detect it for about a day; confirmatory testing such as GC-MS can find traces for up to three days.
How long does heroin stay in your blood?
Only 1 to 2 hours. Heroin's half-life is about 30 minutes, so blood testing is impractical for anything but immediate confirmation.
How long does heroin stay in hair?
Up to 90 days. Hair testing offers by far the longest window and is used where a historical picture matters.
How long does heroin stay in saliva?
A very short period — often under an hour, sometimes a few hours depending on route. Saliva testing is rarely used for heroin because of this.
What do heroin tests actually detect?
Morphine, mainly. Heroin metabolises into morphine almost immediately, which is why tests look for the metabolite rather than heroin itself.
Why is heroin's half-life so short?
About 30 minutes, which is unusually fast. It is a major reason people redose repeatedly through a day and why dependence develops quickly.
When does heroin withdrawal start?
Usually 6 to 12 hours after the last dose, peaking within 24 to 72 hours. The short half-life means symptoms arrive fast.
Can secondhand exposure cause a positive test?
Very unlikely. Passive exposure does not typically produce detectable levels. Direct contact with residue or accidental ingestion could in rare cases.
Is most street heroin actually heroin?
Increasingly not. Fentanyl is widespread in the supply, and it has a different detection profile and a different withdrawal course. If you are unsure what you have been using, say so at assessment.
Is heroin withdrawal dangerous?
Rarely fatal in itself, but severe enough that most unsupervised attempts fail. The serious danger is afterward, when tolerance has dropped and a previous dose can kill.
Woodstock & Hiram, GA
The danger is the week after, not the week of.
One conversation tells you whether outpatient detox is a fit, what your insurance covers, and how soon you could start.
678-506-7611
Woodstock ·
Hiram ·
Mon–Fri 7:00 AM – 7:00 PM
Sat–Sun 9:00 AM – 12:00 PM