By Edmund Murphy

Last updated: 11 July 2023 & medically reviewed by Dr. Kimberly Langdon

Heroin is a potent opiate that is highly addictive. Though it has a relatively short half-life, traces of the drug can linger in the system long after the last dose.

Key takeaways:

  • Heroin metabolizes into morphine which has a half-life of up to seven hours, and 6-acetyl morphine just 25 minutes.

  • Most standard urine tests can detect heroin between one and three days after last use.

  • Poppy seeds, commonly found on bread, muffins, and bagels, can cause a false-positive result for opiates including heroin on most standard drug tests.

How Long Does Heroin Stay in Your System?

How long does heroin last?

Heroin’s half is extremely short, metabolizing into 6-acetyl morphine within as little as six minutes. It also metabolizes into morphine which has a half-life of up to seven hours, and 6-acetyl morphine just 25 minutes. These opioid components of heroin take 5 x their half-lives to be fully removed from the body, meaning morphine will be out of the system in 35 hours, and 6-acetyl morphine in just over a couple of hours.[1]

Even though the opioid metabolites in heroin will have left the body in a few days, traces of the drug can be detected in toxicology tests for much longer.

How long does heroin stay in urine?

Urine tests are the predominant form of drug screening/testing throughout the U.S. owing to their low cost, ease of use, and ready availability. Most standard urine tests can detect heroin between one and three days after last use.[3]

How long does heroin stay in blood?

Blood samples are rarely used to test for heroin as the window for a positive result is very small, usually up to a maximum of six hours. Blood tests will usually only be used after accidents or overdoses to determine the cause of death if substances are believed to be involved.[4]

How long does heroin stay in saliva?

Saliva toxicology tests are rarely used for most substances as detection times are short and traces are hard to find. However, studies indicate that 6-acetyl morphine is highly detectable in saliva up to 24 hours after last use.[5]

How long does heroin stay in hair?

Hair follicle testing can date substance abuse for up to six months of last use for most forms of drugs and alcohol. Heroin can be detected in hair for up to 90 days, potentially longer for heavy users.[6]

Click here to learn how long other drugs and alcohol stay in your system.

Factors that affect heroin detection times

There are many factors that can influence the detection rate in a toxicology test and these can vary from person to person. 

Factors that influence heroin metabolite detection rates include:

  • Length of time heroin was abused
  • Quantity taken
  • Purity of the drug
  • Whether other substances were taken (such as alcohol or other depressants) 
  • Body mass index (BMI)
  • Gender
  • Age 
  • Pre-existing medical conditions (especially those involving the liver or kidneys)

Can you get a false-positive result for heroin?

Poppy seeds, commonly found on bread, muffins, and bagels, can cause a false-positive result for opiates including heroin on most standard drug tests. Trace amounts of codeine and morphine can be found in poppy seeds as they are the base form of opium.[7]

Though most of the metabolites are removed from the seeds when processed, there are enough left behind to cause a false positive if they have been consumed recently. Depending on the amount ingested, poppy seeds may lead to a false-positive up to 60 hours after eating in a urine test.[8]

Heroin addiction treatment

When choosing a treatment center, someone suffering from heroin addiction should consider seeking input from a licensed professional who specializes in addiction. This way, they can receive clinical guidance about what options are available to them, and which treatment might best meet their needs. 

There are numerous treatment programs ready to help those struggling with heroin addiction. Our rehab directory can help you find a treatment option that is right for you and allow you to get the help you need, today.