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How Long Does Heroin Stay In Your System?

Dr. Alan Weiner MD

Medically reviewed by

Dr. Alan Weiner, MD

March 18, 2019

Regardless of the form, heroin is a dangerous drug that holds the capacity to cause great harm upon a person’s life. In order to combat the growing concerns of heroin abuse and addiction, it is important to understand the way this drug impacts a user so that we are better prepared to embrace preventative measures, especially that of overdose, and treatment of this drug.

Heroin is a drug of abuse with a widespread impact across our country, a drug that is in part responsible for the acceleration of the current opioid epidemic we now face as a nation. Within the opioid class of drugs, heroin is a derivative from the opium poppy plant, specifically, it is synthesized from morphine, another powerful opioid drug. Heroin occurs in several forms, including a powder or a form that is reminiscent of roofing tar, hence the name “black tar heroin.”

How Does Heroin Impact A User?

Heroin itself has a surprisingly brief half-life of only a few minutes, according to Mayo Clinic (though other entities report differing estimates of the half-life, varying from three minutes to a half-hour); however, what is of concern, is the chemical changes that happen to this drug when it enters your system. It is in fact these changes that are responsible for exerting the hallmark feelings typically associated with heroin abuse.

Known for its influence in inducing a “rush,” and/or state of euphoria, heroin attaches to, and switches on mu-opioid receptor sites within your brain’s reward center, releasing an important neurotransmitter called dopamine, which then creates the feelings of intense pleasure attributed to heroin use. It is at this point, when heroin is actually turned back into morphine, that a user experience a rush.

The following information is adapted from New York University’s Steinhardt’s Center for Health, Identity, Behavior and Prevention Studies, and details each mode of administration and the rate, and way, by which heroin’s effects are felt. The exact way, and speed by which heroin affects a user is dependent on the means that a person chooses to administer the drug by and also the dosage.

  • Intravenous (IV) injection — Both the “rush” and feelings of euphoria are felt fairly immediately, in roughly seven to eight seconds.
  • Smoking — A user will be overcome with an “adrenaline rush” that is unique to this means, in about two to five minutes.
  • Intramuscular injection — A user encounters a “rush” around the five to eight minute mark.
  • Snorting — A user will experience a “rush” in approximately ten to 15 minutes.

Various other symptoms accompany these sensations, as detailed by the National Institute on Drug Abuse, including dry mouth, intensely itchy skin, gastrointestinal upset, including nausea and vomiting; a sense of heaviness in your limbs, and the feeling of your skin becoming warmer and flushed. Following these sensations, a person will typically encounter a more sedated state, feeling drowsy and removed from their surroundings, with impaired cognitive functioning, and both slowed respiratory and cardiac functions. In some cases, the latter two may be so severe as to cause death.

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Overall, heroin’s effects may linger beyond these time frames—with, as asserted by Medscape, “Heroin’s peak therapeutic and toxic effects are generally reached within 10 minutes with intravenous injection, within 30 minutes with intramuscular injection or when snorted, and within 90 minutes when injected subcutaneously.” In addition, they tell us that heroin’s analgesic (or pain-relieving) properties linger for three to five hours.

Due to its relatively brief half-life, heroin itself, in its whole form is not responsible largely for the way a user feels, instead, it is the resultant morphine which vastly dictates a user’s experience. NYU Steinhardt elaborates, stating that “Heroin acts as a lipid soluble “prodrug” within the brain, meaning that heroin itself is inactive but it is metabolized into an active form within the body.” A Medscape article does tell us that a very small portion of the sensation attributed to heroin use, the “initial rush,” may actually be due to the drug in its whole state, because of this “high lipid solubility and rapid penetration to the brain.” What happens then? In order to better understand the length of time that heroin—and its metabolites—remain in your system, we must first seek to better understand what happens when it enters, and is metabolized, within your body and brain.

Understanding The Chemical Process That Occurs After You Use Heroin

It is critical to understand that heroin’s effects linger within your body and brain even after the rush and sense of euphoria subsides. This understanding is pertinent in reducing risk of overdose. Far too often, users mistakenly think due to the decreased sense of the drug’s effect, that it has exited their system—thus they take another dose, compounding what is yet within their system (estimated to be around 50 percent of the drug’s components), in a way that could have fatal results.

Again, when you take heroin, it is quite rapidly changed to its progenitor morphine, another very potent opioid drug. It is what happens in this process—heroin changing to morphine—that interests us, as well as the length of time it takes for the morphine to exit an individual’s system. Once heroin passes your blood-brain barrier, it is rapidly changed into 6-monoacetylmorphine (6-MAM) (the chemical metabolite many drug tests look for). This metabolite is then changed to morphine, a drug that has a half-life of two to three hours, as noted by Medscape.

How do these processes equate to time? A study presented by the U.S. National Library of Medicine, found that “The mean half-life of heroin (+/- S.D.) after intravenous injection or infusion was only 3.0 +/- 1.3 minutes, and the mean clearance of heroin from the blood at apparent steady state was 30.8 +/- 2.1 ml per kilogram of body weight per minute.” A Mental Health Daily article offers an example of heroin metabolism and clearance, reporting that at a half-life of one and a half to seven hours (a larger window than reported by Medscape) “ the morphine (resulting from heroin ingestion) could stay in your system for 1.60 days before it is fully eliminated.”

Are There Certain Factors That Alter The Way This Drug Acts Within A Person’s Body?

Though research has established a baseline, a person may experience a different outcome in how long it takes for heroin to completely leave their system, due to the means of administration, dosage taken, the frequency a person uses the drug, and the personal circumstances and characteristics within each person’s life. Here, we detail this information on this, as provided by the Mental Health Daily article:


Heroin can vastly differ in its purity, as it is often cut with various foodstuffs, chemicals, and even other drugs. When a dose of heroin has a higher purity, there is more drug present, hence, as the article reports, it may remain in the user’s system for a longer time period.

Method of Administration

As previously mentioned, the means by which a person chooses to take the drug may vastly alter the rate in which the drug enters their system, crosses the blood-brain barrier, and become metabolized and broken down into the various metabolites. Additionally, the article notes that it is theorized that the way the drug is taken may affect the rate by which your body is able to clear the drug from its system. The differences are as follows:

  • Orally — This route offers the lowest level of bioavailability, at roughly 35 percent, with 6-MAM being notably harder to detect, due to the fact the drug undergoes a “first-pass metabolism in the liver,” which inhibits both it, and its metabolites, from remaining in the body for a longer period of time.
  • Snorting — The number of metabolites are two to six times lower than those that occur with IV injection. Additionally, the grade of heroin used for snorting is often times less pure, thus it may not remain in the body for as long.
  • Smoking — Smoking yields a higher bioavailability than the previous modes, though still less than IV injection, falling at 52 percent. This mode often sees a higher grade of heroin than the previous ways and also allows for the drug to bypass first-pass metabolism in the liver, thus both heroin and its metabolites linger in the body longer. Concentrations of 6-MAM are detectable within a minute of use.
  • IV Injection — This route usually uses the highest grade and offers 100 percent bioavailability, thus spiking the levels of 6-MAM within one minute, to the highest of any mode; levels which are detectable longer than with any other means.


In short, the more you take, the longer it takes to metabolize. Higher amounts may exceed your body’s ability to fully metabolize and eliminate the drug, and due to its lipid (fatty) nature, this excess may be stored in your body’s fat reserves until your body catches up and is able to process it out.

Frequency of Use

Inexperienced users have a tendency to metabolize the drug quicker, as they, with a decreased tolerance, have a tendency to take smaller amounts. Inversely, more chronic users who may use several times a day, may find that their body cannot keep up with the greater amount of the drug flooding their system, thus some of it remains within the fat tissues, taking a greater time to completely eliminate.

Personal Factors

Like every drug of abuse, each person who uses and abuses it is affected in a different way—various factors that are unique to each individual have the potential to alter how heroin is metabolized within their body once it enters their system, including:

  • Age — As a person ages, their ability to metabolize a drug may change as these processes slow down; hence an older person may take longer to clear the drug from their system.
  • Dietary Concerns — It is theorized that individuals with a greater level of hydration and/or a better diet may more effectively metabolize this drug.
  • Body mass — The higher the proportion of heroin to a person’s body mass index, the slower they may be able to metabolize it.
  • Genetics — Various research theorizes that certain genetic polymorphisms alter the speed by which a person can pass this, and other opioid drugs, specifically a gene for CYP2D6 (a liver enzyme), which creates the following metabolic categories “ultra-rapid metabolizers (UMs), extensive metabolizers (EMs), intermediate metabolizers (IMs), and poor metabolizers (PMs).” Thusly, as the article outlines, those at the lower end (the PMs) may take longer to eliminate the drug.
  • Liver function — The liver is vastly responsible for processing heroin, hence, if your liver isn’t working properly, or efficiently, you may not pass the drug as quickly.
  • Metabolism — A slower, overall metabolism may delay drug metabolism and excretion.
  • Polydrug or supplement use — The articles suggests that certain drugs or supplements could either slow down, or quicken, the detoxification process.

Don’t Let This Drug Consume Anymore Of Your Life

Any addiction has the power to drastically alter a person’s life. Heroin, as one of the most addictive drugs known to man, wields this influence in even greater force. Despite this, help exists—it is possible to overcome heroin abuse or addiction and learn how to live a more fulfilling, drug-free life. desires this for you or your loved one, and we want to help you find the inspiration, resources, and treatment options that are so crucial to beginning, and succeeding, at this journey. Don’t wait any longer—contact us today, so that we can help you get started on a path away from the destruction of heroin and towards the wellness of sobriety.

National Institute on Drug Abuse - Heroin

Medscape - Heroin Toxicity: Pathophysiology

U.S. National Library of Medicine - The pharmacokinetics of heroin in patients with chronic pain

Mental Health Daily - How Long Does Heroin Stay In Your System

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