How Long Does Heroin Stay in Your System?

Detection Timetable Depends on Many Variables

Man Filling Syringe With Heroin
The Danger of Heroin Overdose Is High. © Getty Images

Determining exactly how long heroin is detectable in the body depends on many variables, including which kind drug test is being used. Heroin - also known as Diacetylmorphine, horse, smack, dragons tail, smack, junk, H - can be detected for a shorter time with some tests, but can be "visible" for up to three months in other tests.

The timetable for detecting heroin in the system is also dependent upon each individual's metabolism, body mass, age, hydration level, physical activity, health conditions and other factors, making it almost impossible to determine an exact time heroin will show up on a drug test.

The following is an estimated range of times, or detection windows, during which heroin can be detected by various testing methods:

How Long Does Heroin Show Up in Urine?

Heroin is detectable in a urine test for 2-4 days.

How Long Does Heroin Stay in the Blood?

A blood test will detect heroin for up to 6 hours.

How Long Will Heroin Show Up in a Saliva Test?

A saliva test will detect heroin from 1-4 days.

How Long Does Heroin Remain in Hair?

Heroin, like many other drugs, can be detected with a hair follicle drug test for up to 90 days.

How Is Heroin Eliminated From the Body?

Like most drugs, the main way heroin is eliminated from the body is via the kidneys in urine, but it can also be excreted via sweat, tears, saliva, and feces.

How long heroin will show up on a standard drug test depends on several factors such as your weight, body mass and personal metabolism. However, the main factor in how long heroin is detectable in a drug test is the amount of the drug you have taken.

Heroin will stay in the body only 1 or 2 days if you are a light user, but if you are a heavy, chronic user, it can remain detectable in a urine test for almost a week.

The Danger of Heroin Overdose

One of the main reasons to be aware of how long heroin remains in the system is the risk of overdose. If you take more heroin because the effects of the last dose have worn off, but the drug is still in your system, it could cause an accidental overdose.

Here are some of the symptoms of a heroin overdose:

  • Shallow, slow or difficult breathing
  • Dry mouth
  • Extremely small pupils (pinpoint pupils)
  • Discolored tongue
  • Low blood pressure
  • Weak pulse
  • Bluish-colored nails and lips
  • Constipation
  • Spasms of the stomach and intestines
  • Coma
  • Delirium
  • Disorientation
  • Drowsiness
  • Uncontrolled muscle movements

The above symptoms are related to an overdose of heroin alone. Heroin sold on the street many times is mixed with other substances or drugs that can cause their own set of symptoms.

Street heroin cut with the powerful painkiller fentanyl has caused a noticeable increase in overdose deaths in the United States and has proven to be extremely dangerous.


Always Test Clean. "What Are Drug Detection Times?" Drug Test Facts Accessed June 2015

American Association for Clinical Chemistry "Drugs of Abuse Testing." Lab Tests Online. Revised 2 January 2013.

LabCorp, Inc. "Drugs of Abuse Reference Guide." Accessed March 2013.

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