What Is A Lethal Dose Of Heroin?

There is no known lethal dose of heroin. There have been multiple studies done on a variety of animals to test the lethal dose of heroin, but no conclusive number was established.

Research suggests that there’s no way to determine a lethal dose because each animal, and person, responds differently to varying amounts of heroin.

Learn more about the lethal dose of commonly used drugs

The Process Of Determining The Lethal Dose Of Heroin

Heroin is a Schedule I drug, meaning it’s within a class of drugs with no medical uses and a high potential for abuse. Most street packets of heroin will contain about 3 to 30 milligrams (mg). As far as studies have shown, a dose of 30 mg does not induce death. It is assumed that a person who uses heroin will likely overdose if they ingest more than the normal amount of heroin than their body is used to, but death is unlikely.

Though heroin overdose is dangerous and potentially lethal, research has concluded that most heroin-related deaths also involved other substances. In instances of death, autopsies most frequently showed the presence of central nervous system depressants such as alcohol and benzodiazepines (benzos).

How Likely Is A Fatal Heroin Overdose?

Heroin-involved overdose deaths have shifted dramatically in recent years due to fentanyl contamination of the drug supply. While heroin-involved deaths peaked at 15,469 in 2016 and declined to 3,984 in 2023, the proportion of those deaths that also involved illicitly manufactured fentanyl increased to 80% in 2022 and remained high through 2023, meaning most people who died from “heroin” were unknowingly consuming fentanyl.

The highest risk of fatal overdose comes from polydrug use, combining heroin or fentanyl-laced heroin with alcohol, benzodiazepines, or other depressants compounds respiratory depression in ways that can be rapidly fatal. The unpredictability of today’s drug supply, where any batch of street heroin may contain a lethal concentration of fentanyl, makes the risk of accidental overdose much higher.

Mixing Heroin And Depressants Can Be Lethal

Heroin is a central nervous system depressant, so mixing it with other depressants such as benzodiazepines, alcohol, and sleeping medications can be extremely dangerous. When two depressants are mixed into the bloodstream, the substances enhance each other. This can cause suppression of vital bodily functions, such as respiration rates.

While heroin alone may not be enough to cause a person to fatally overdose, there is a major risk of organ failure when substances like alcohol or benzos are in the mix.

Warning Signs Of A Heroin Overdose

If you or a loved one have been using heroin, it’s important to be aware of the signs of overdose. A heroin overdose can be treated if it’s found early enough and treated by medical professionals.

Signs of a heroin overdose include:

• slow or labored breathing
• extreme drowsiness
• dry mouth
• very small pupils
• low blood pressure
• weak pulse
• coma
• disorientation

Find Treatment For A Heroin Addiction

If you or a loved one are facing a heroin addiction, help is available. Many rehab programs throughout the country offer specialized care for people with opioid use disorder.

Treatment options may include:

• inpatient rehab programs
• dual diagnosis treatment
• counseling
• medical detoxification
• group therapy
• family therapy
• outpatient rehab programs
• 12-step recovery groups
• medication-assisted treatment (MAT)

Browse our directory or reach out to the Substance Abuse and Mental Health Services Administration (SAMHSA) for more helpful information about addiction treatment.