Get a free, confidential consultation.

How Long Does It Take for an
Overdose to Kick in?

How long a drug overdose takes depends on a number of factors. Learn what contributes to the duration of fatal and nonfatal overdoses, how drug tolerance comes into play, the dangers of overdosing after recovery, and opioid overdose facts.

person overdosed on drugs
Typically, the time it takes for a drug to cause an overdose or death depends on many factors including:
  • The specific drug(s)
  • The dosage and duration of abuse
  • Method of use (injected, smoked, swallowed or snorted)
  • Coexisting physical illnesses/conditions
  • Individual’s age
  • Body weight

In general, it takes more of a drug to cause an overdose in someone who is used to taking the drug and has developed a tolerance than in someone who has never used it before.1

Prompt medical intervention or the lack thereof plays a crucial determining role in overdose outcome.

How Long Do Nonfatal Overdoses Last?

The immediate side effects of a nonfatal opioid overdose can last from minutes to hours, although one has to consider numerous potential long-term side effects. When one talks about how long an overdose lasts, in terms of a nonfatal overdose, the consequences can last forever, resulting in devastating, lifelong health problems.

While drug overdose deaths attract considerable public attention, there are substantial consequences of nonfatal overdose, including cardiac and muscular problems, brain damage and cognitive impairment, renal failure, hearing loss and injuries sustained during overdose. In severe cases, overdose-related brain injuries can leave people in a vegetative state.5

Overdose infographic

How Long Do Fatal Overdoses Last?

A fatal overdose can happen in a matter of seconds or hours. Anecdotal answers on overdose times can be found in online drug forums and sometimes in published coroner reports. People often overdose alone and are found hours later. Therefore, in many cases, there is not a definitive answer regarding the length of time between the fatal dose and the person’s death.

What Role Does Drug Tolerance Play in Overdoses?

Short periods of abstinence erode one’s tolerance:

  • After just two or three days of abstinence, tolerance decreases by 25% or more.
  • After a week of abstinence, 50% to 75% of tolerance is lost.
  • If a person has not used for a month, tolerance is down to zero.
  • It is not uncommon for a person in recovery to die of an overdose when they start using again due to decreased tolerance.2


Peaches Geldof’s Overdose After Recovery

A widely publicized example of an overdose death following recovery was that of British television personality and model Peaches Geldof. She died of a heroin overdose in April 2014. At the time of her death, she had been in recovery for more than two years and was in a drug treatment program supplemented with prescription methadone. Unknown to her husband, she had recently relapsed and failed a drug test.3

How Did Peaches Geldof Overdose?

Here’s what is known about the details surrounding Peaches’ Geldof’s death:

  • The syringe filled with the residue of the fatal dose was found in a box filled with sweets by the side of her bed.
  • Police officers later found nearly 80 syringes, some of which were used with spoons for preparing the heroin, as well as 27 bottles of methadone.
  • Her husband last spoke to her at 5:40 p.m. on Sunday, April 6, and when he could not get in touch with her later by phone, went there the next morning and discovered her body.
  • Geldof’s estimated time of death was at or just after 8 p.m., but it is unknown when she took the lethal dose.3

Opioid Overdose Facts

  • According to the Centers for Disease Control and Prevention, opioid abusers are six to 20 times more likely to die than non-opioid using peers of a similar age.
  • Heroin and other opioids can cause calmness and drowsiness, but they also suppress the respiratory system. When a person sleeps under normal circumstances, the body “remembers” to breathe. When a person overdoses on an opioid, this leads to asphyxia (lack of oxygen) and respiratory depression (lack of breathing), a common biological cause of death resulting from opioid overdose.1,2
  • A fatal overdose varies between 75 mg to 600 mg, based on the purity of the drug.
  • Overdose death can occur within minutes of dosing, but more commonly takes a period of hours after use, during which time the person is unresponsive and often snores loudly.
  • Anecdotal reports suggest that when heroin is taken by injection, an overdose hit can lead to loss of consciousness within seconds.
  • An estimated 50% of all heroin overdose deaths occur when a person chooses to use it with no one present to resuscitate, call 911 or administer naloxone.
  • When heroin is mixed with central nervous system depressants such as alcohol or benzodiazepines, an overdose can be immediate due to rapid metabolism of the opioid drug. Conversely, researchers found injecting cocaine (a stimulant) and heroin together increased the overdose risk by 260% due to cardiac arrest.1,2
  • Hypoxic brain injury, caused by a lack of oxygen to the brain, is an underreported repercussion of heroin overdose. The long-term consequences of hypoxia depend on how long the brain is deprived of adequate oxygen. The longer a person is not breathing, the greater the potential for brain damage. Health outcomes depend on the success of damage control measures and the area and extent of impacted brain tissue.4


  1. How long does it take a person to die from acute hydrocodone/morphine/heroin toxicity? When it happens, how long does it take for the body to shut down? Quora website. Accessed April 17, 2017.
  2. How to Prevent, Identify and Respond to Opioid Overdoses. Choose Help website. Accessed April 17, 2017.
  3. Peaches Geldof inquest: Tragic final days of mother-of-two’s life reveal she lied to husband about failed heroin tests. Independent website. Published July 23, 2014. Accessed April 17, 2017.
  4. Overdose Basics. International Overdose Awareness Day website. Accessed April 17, 2017.
  5. Even non-fatal overdoses can lead to severe consequences. Published September 2, 2014. Accessed April 17, 2017.
  6. How long do you stay in the hospital after an overdose? Quora website. Accessed April 17, 2017.

Get a free, confidential consultation.
Call 844-876-5568 or fill out the form below.