How Long Does Heroin Stay in Your System?

2 min read · 5 sections

Heroin is an illegal opioid, classified as a Schedule I controlled substance in the US due to its addictive quality, damaging nature, and the fact that it has no approved medical use in the country. It’s typically smoked, snorted or injected straight into one’s veins for a fast, euphoric high, followed by sensations of contentment, relaxation, and sleepiness.

Heroin can be detected in the urine for up to 48 hours, blood for up to 5-6 hours, saliva for up to 5-6 hours, and hair for up to 3 months or more. These times may change based on the test used, and whether heroin was used long-term.

Heroin Effect Duration & Half-Life

Heroin’s effects last longer than the effects of drugs like cocaine and meth, but it has a particularly short half-life of only 30 minutes. This means that if a user takes a single dose of heroin, it will take 30 minutes for half of the drug in the person’s system to be flushed out. Some studies suggest that this half-life is as short as 3-8 minutes.
The actual time this takes for each individual depends on a number of factors, including:

  • Height and weight
  • Age
  • Genetics
  • Body fat content
  • The amount taken
  • The quality of the drug
  • Metabolism rate
  • Health of the liver and kidneys
  • Hydration

How Long Does Heroin Stay in Your System?

The rate at which heroin exits the body, of course, affects how long it will take before the substance is no longer detectable in various drug tests. The drug tests approved by the Food and Drug Administration (FDA) for heroin are those for the blood, saliva, urine, and hair follicle.1 Newer, more advanced tests can detect traces of heroin in the system for a longer period of time since the last dose. Many tests now look for heroin metabolites, which are created when the liver metabolizes the drug. These stay in the system much longer than the actual intoxicant.

Most of the time, heroin is no longer detectable in a person’s urine after just 2 days.2 However, certain tests have been known to have a positive result for this drug for up to 7 days. Blood and saliva tests aren’t often used for heroin due to the fact that this opioid, like many others, has such a short half-life. It can therefore take only 5-6 hours for the drug to become undetectable in these fluids, though they can possibly be found for up to 2 days. The only test that works for longer than a week is the hair follicle test, which can detect heroin for up to 3 months or more. However, there are many possible factors that can interfere with hair tests. It’s also important to note that heroin can generally be detected much longer in the systems of long-term, heavy users. This is because excessive use causes the drug to be stored in fatty tissues that take much longer to be flushed out than substances that are merely in the blood and other bodily fluids.
To summarize how long heroin stays in your system:

  • Urine: 48 hours or 2 days, with certain tests showing up to 7 days
  • Blood: 5-6 hours, with certain tests showing up to 2 days
  • Saliva: 5-6 hours, with certain tests showing up to 2 days
  • Hair: Up to 3 months or more

Heroin is considered to be one of the most addictive drugs in the world. Alarmingly, heroin use has been on the rise in recent years, with the number of first-time users rising from 90,000 in 2006 to 156,000 in 2012.3 Its use is spreading, from being concentrated primarily in poor, urban areas to more suburban and affluent neighborhoods. The pull of heroin can be strong, but there are many treatment options for this type of drug, including medication, rehabilitation centers, and addiction therapy. No one is beyond help when it comes to addiction, no matter how bad the problem may seem.

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Finding Heroin Treatment Near You

Heroin addiction is a large problem that should be handled with the proper professionals. A drug detox or rehab program may be right for you. If the cost of finding treatment is preventing you or a loved one from seeking help, insurance may be able to cover all or part of the cost of treatment. Find out instantly below.

Additionally, American Addiction Centers has rehab facilities across the United States. Explore the various amenities and treatment programs below.

Infographic on Timeline of Heroin in the Body

How long does heroin stay in your system


  1. U.S. Food & Drug Administration. (2018). Drugs of Abuse Tests.
  2. MedlinePlus. (2019). Toxicology Screen.
  3. National Institute on Drug Abuse. (2021). What is the scope of heroin use in the United States?
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