How Long Does Heroin Stay in Your System?

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

Heroin is an opiate drug made from morphine. It is not legally available by prescription in the United States, although it is available on a limited basis in Canada, Netherlands, and the United Kingdom to treat heroin addiction. Using heroin brings a high risk of overdose and dangerous interactions with other drugs and prescribed medications. Knowing how long it could be active in your system can help you understand the risks and variables.

How Heroin Acts in Your System

Heroin sold on the street is manufactured illegally and differs widely in strength, purity, and what other substances it is mixed with. Nonmedical users take heroin in many different ways, each of which can affect how soon and how long its effects are felt. Heroin can be smoked, injected, or snorted.

The effects of heroin are felt swiftly. Depending on the dose, a wave of intense euphoria lasts 45 seconds to a few minutes, with the other effects peaking for one to two hours and most effects wearing off in three to five hours, although sedation can last longer.

Heroin has an extremely rapid half-life of 2 to 6 minutes and is metabolized to 6-acetylmorphine and morphine. The half-life of morphine is 1.5 to 7 hours and the half-life of 6-acetylmorphine is 6 to 25 minutes. It takes four to five half-lives of a drug for it to be effectively eliminated from the system.

Heroin and 6-acetylmorphine enter the brain more readily than morphine. In the brain and nervous system, these substances act on receptors involved with euphoria, pain suppression, depressing breathing, reducing gastrointestinal activity, drowsiness, dysphoria, delusions, and hallucinations.

Common effects are a surge of euphoria followed by a drowsy twilight state alternating between wake and sleep. Physical effects include constricted pupils, feelings of nausea, flushed skin, and dry mouth, and a feeling of having heavy hands and feet.

Heroin is highly addicting, and once addicted the user risks withdrawal symptoms if they don't have access to heroin. Withdrawal symptoms can begin 6 to 12 hours after the last dose and last for 5 to 12 days.

The Danger of Heroin Overdose and Interactions

While heroin is in the system, the user is at risk of interactions with other drugs and substances as well as overdose. Street heroin varies in purity from 11 to 72 percent, and it is often combined with ketamine, cocaine, diphenhydramine, alprazolam, and MDMA (ecstasy).

Heroin depresses the respiratory system and slows the heart rate, so there are risks of interactions that can lead to coma. Dangerous interactions might happen with barbiturates, benzodiazepines, antidepressants, MAO inhibitors, and antihistamines.

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 difficulty 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 

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 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 taken. Heroin will stay in the body only one or two days for a light user, but for a heavy, chronic user, it can remain detectable in a urine test for almost a week.

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Article Sources

  • Heroin. National Institute on Drug Abuse.
  • Morphine (and Heroin). National Highway and Transporation Safety Administration.