How Long Does Heroin Stay in Your System: Based on Science

how long does heroin stay in your system

Heroin is an opioid drug made from morphine, a natural substance derived from the seed pod of different opium poppy plants grown in Mexico, Southeast and Southwest Asia, and Colombia. The opioid is commonly known for its painkilling effects and is used in hospitals to relieve pain in cancer patients and those recovering from surgery.

The length of time heroin stays in the body depends on several factors, including the amount taken, user’s metabolism and history. Typically, heroin has a short half-life and is only detected for 5-6 hours to 2 days in blood and saliva tests. Hair follicle tests work for a longer time and can detect heroin for up to 3 months.

This article will focus on how long heroin stays in your system, whether it can be detected by various drug tests, how to flush it out of your system fast, what can trigger a false positive heroin test and the factors that influence the detection time.

How Long Does Heroin Stay in your System

Heroin is an opioid drug that can be used for both medical and recreational purposes. It is illegal to sell, possess, or make heroin without a license because this drug is classified and controlled under Schedule I and IV of the Single Convention on Narcotic Drugs in the US.

Typically, it’s one of the most potent and addictive opioids. It goes by street names big H, horse, hell dust, and smack. It can be injected, smoked, snorted, or inhaled into your body. When smoked or injected, it takes about 5 to 20 seconds before the ‘rush of euphoria’ is felt.

When snorted, however, it might take a little longer, up to 2 minutes. Some people also mix heroin with crack cocaine, and this is known as speedballing, which cause an even faster effect.

In as much as this drug stays in the system for a short length of time, its effects are very intense. It lasts for about three to six minutes before it’s broken down into morphine and 6-acetylmorphine.

Morphine has a half-life of two to seven hours while 6-acetylmorphine has a half-life of up to 25 minutes. It will, however, take several half-lives and varying durations for heroin to be entirely flushed out of your system.

In most cases, heroin can no longer be detected in a person’s urine after about 2 to 3 days. However, certain urine tests are known to have a positive result for up to 7 days after the last use. This is highly dependent on the amount and the method in which it was consumed.

Blood and saliva tests, on the other hand, are not often used for heroin detection due to the fact that this opioid, like many other drugs, have such a short half-life. Opioid has a window detection period of 5 to 6 hours.

Heroin can be detectable in hair follicles for a much more extended period than any other part of the body. The test can easily detect heroin in your system for up to 3 months.

Can Heroin Be Detected by a Drug Test?

Heroin goes through rapid metabolism and is later excreted by the kidneys in the form of urine. The metabolism process produces morphine and 6-acetylmorphine. Therefore, most drug tests will detect these two substances rather heroin itself.

The components that are tested are as follows:

Blood Test

Heroin metabolizes quickly and stays in the system for a relatively short period. It’s present for about 12 hours in the blood after the last ingestion. In some cases, however, it can be detected for up to a day depending on the frequency of use and how much was consumed.

Urine Test

Heroin urine sample is analyzed for the presence of diacetylmorphine and other metabolites. You will test positive two to four days after the last time you ingested the drug. However, a sample of regular or chronic users can show evidence of use up to seven days after the last dose.

Saliva Test

Heroin is mostly detectable for about 24 to 36 hours in saliva, which is much shorter than urine or hair tests. However, some opiates may have a much longer detectable period.

Hair Test

The hair follicle test is the only test that can detect heroin for more than a week. This test can detect the presence of heroin up to three months since the last dose. The detection window can increase for long-term, heavy users.

How to Quickly Flush Heroin Out of Your System

Heroin metabolizes quickly and will be undetected by most standard drug tests after about three days. However, to flush it out of your body much faster, here is what you can do:

Drink More Water

Having more water in your system enables the kidneys to filter the blood better and flush out heroin.

Eating Healthier Foods

Foods such as fruits and vegetables enable your body to be healthy, allowing you to work and feel better.

Avoid Caffeine

Caffeine is a bad idea because it makes it more difficult for the drug to leave the system.

Exercise Regularly

Exercises increase the metabolic rate in the body. This not only helps the body to be a lot healthier, but also eliminates any toxins faster.

Avoid Mixing Heroin and Alcohol

A mixture of alcohol and heroin will always make it harder for the drug to leave the system.


The surest way of flushing it out of your system is by stopping its usage and allowing your body the time to eliminate it naturally.

Heroin withdrawal symptoms

These withdrawal symptoms may start to appear anywhere between 6 to 24 hours after the last dose of heroin. As heroin and morphine compounds are eliminated, your body struggles to adapt without them. This leads to the following withdrawal symptoms:

  • Vomiting
  • Nausea
  • Dilated pupils
  • Sweating
  • Tearing
  • Insomnia
  • Shaking
  • Muscle aches
  • Anxiety and agitation
  • Abdominal cramps and diarrhoea

What Can Trigger a False Positive Test for Heroin

A false-positive result after the ingestion of poppy seeds can occur in urine drug tests. Poppy seeds contain morphine and codeine. Therefore, ingesting foods containing these seeds will cause some traces of morphine in the urine. Cough suppressants too, especially those containing codeine and some quinolone drugs can also trigger positive opiate results.

However, it should be noted that finding morphine after ingesting poppy seeds or using a codeine cough suppressant would not be a false positive. These are true positives since the detected drug really is/was present though not clinically significant positives.

Which Factors Influence Detection Time

Some factors can significantly contribute to the duration in which heroin can be detected in the system. These include:

Amount consumed

If heroin is consumed frequently and in high doses, it can result in high urine morphine concentrations of up to 2000 mg/mL for a period of 6 to 12 hours after ingestion.

Weight of an Individual

Heroin will stay longer in the systems of overweight individuals than those classified as ‘normal’ weight by BMI. This is usually due to the fact that traces of heroin may be trapped in the fatty tissues of overweight persons and end up staying there a bit longer.

The Age of an Individual

As an individual age, it takes longer for their systems to metabolize toxins, thereby lengthening the detection time of heroin.

The Rate of Metabolism

Our metabolism differs from one person to another. Therefore, some people will be genetically predisposed to quickly or slowly metabolizing heroin. With a faster metabolism, heroin is used up by the system quickly than with a slower metabolism.

The Method Used

Heroin can be smoked, sniffed or intravenously injected. When smoked or sniffed, it’s metabolized quickly and eliminated in urine. Injecting it into the veins, however, allows some of it to be retained in body fluids for much more extended periods.

The Duration of Use

Individuals who use heroin more frequently are more likely to retain it in fatty tissues and body fluids for more extended periods, unlike occasional users.

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