How long opioids stay in your system is influenced by various factors. One of the most important ones is its half-life, a term we’ll explore later in the article. But things like body composition, history of drug abuse, and even the type of opioid you’re using plays a huge role in how long they stay in your system. Understanding how long an opioid stays in your body is essential because it tells you:

  • How long do the effects last
  • When to expect withdrawal symptoms to appear
  • How long must someone stay drug-free to pass a specific drug test
  • What to do in case of an overdose 

What’s Opioids Half-Life

“Half-life” or “elimination half-life” is the period for the dose of a substance to decrease by half. After the half-life, only half of the original dose is still in your body. Once the half-life passes, the rate of elimination slows down. 

Most drugs take between 4 and 5 half-lives.

In terms of how long they stay in your system, opioids are classified as short-acting and long-acting opioids. Let’s break down their durations.

Short-Acting Opioids

Short-acting or immediate-release opioids are opioids that take effect very shortly after taking them and whose effects last for short periods, generally no more than four to six hours. Commonly prescribed short-acting opioids include:

  • Oxycodone
  • Morphine
  • Hydrocodone
  • Codeine

Long-Acting Opioids

Long-acting or extended-release opioids take longer to kick in but tend to have more prolonged effects. They’re used to treat chronic pain conditions. Examples of long-acting opioids include

  • Oxycontin
  • Methadone
  • Butrans
  • Fentanyl

How Long Do Opioids Stay in Your System?

The body breaks down opioids very similarly. The liver and kidneys metabolize most opioids to eliminate them through the urine. However, opioids can stay in your blood, saliva, and hair at different times. 


This is the most common form of testing for opioids. Opioids stay in the waste matter present in urine from a few hours to a few days. Although the specific drug is sometimes impossible to identify if enough time has passed, the test may identify some of its metabolites (metabolic byproducts). Here’s an average timeline of how long certain opioids stay in your system:

  • Hydrocodone: between 2 and 4 days
  • Oxycodone: between 2 and 4 days
  • Codeine: between 1 and 2 days
  • Morphine: between 2 and 3 days
  • Fentanyl: approximately 24 hours
  • Methadone: about 3 days but can be up to 2 weeks


Blood testing for opioids is uncommon because it’s invasive and has a useful window of less than a day, sometimes less than an hour. Here’s how long specific opioids are still detectable in blood tests:

  • Hydrocodone: approximately 8.8 hours
  • Oxycodone: around 6 hours
  • Codeine: about 3.9 hours
  • Morphine: about 6.7 hours
  • Fentanyl: approximately 12 hours
  • Methadone: approximately 2 to 3 days


Saliva testing can detect opioids for a few hours to a few days. These are some timeline estimates for how long opioids remain detectable in saliva: 

  • Hydrocodone: between 12 and 36 hours
  • Codeine: between 1 and 4 days
  • Morphine: approximately 4 days
  • Fentanyl: saliva testing for fentanyl is unreliable, and there’s no accurate estimate
  • Methadone: approximately 2 days


Hair tests are less common but can also detect opioids in your system. Unlike other bodily substances, hair retains byproducts of drugs like marihuana and opioids for weeks and months. 

The length of the hair sample determines the time window for drug use. For example, a 1.5-inch strand of hair offers a 90-day window.

Hair testing best identifies certain drugs over others, especially cocaine, and oxycodone. Hair can detect byproducts of long-acting opioids for days, weeks, and months.

Factors That Influence How Long Opioids Stay In Your System

The half-life of an opioid is generally short (as short as a few minutes) and varies depending on various individual factors. These factors are:

  • The acid level of urine. The more acid, the less an opioid lasts in urine.
  • Opioid use history. Opioids can build up in your body, so people with a history of opioid use may take longer to clear them.
  • Age. Opioids may take longer to leave an older person’s system than a younger one. 
  • Frequency of use. People who use opioids more frequently for longer periods will likely retain them longer.
  • Medical conditions. People with kidney or liver disease will have more difficulties processing opioids, resulting in longer half-lives. 
  • Dose concentration. Higher doses last longer and take longer to get excreted from the body.
  • Body fat concentration. People with higher fat concentrations retain drugs for longer because some drugs or their byproducts may accumulate in fatty tissues.

Because of these variations, opioids can stay in various organs and substances of our body between a few hours and multiple days or weeks.

The Importance Of Understanding How Long Opioids Stay In Your System

When someone misuses opioids, it is essential to know how long opioids stay in your system. Opioids can appear on drug tests up to 30 days after you last use the drug. This is true whether you are taking opioids illicitly or if the drugs are prescribed to you by a doctor.

It’s important to know how long opioids stay in your system as this can increase your risk of an overdose and affect any treatment you may receive to manage withdrawal symptoms. 

If you or someone you love is dealing with opioid addiction, consider seeking help. Opioid abuse treatment can help you regain control of your life and start your recovery journey. Speak with an addiction specialist today and learn about opioid rehab treatment options. Recovery is possible, you just need to take the first step.