How Long Does Methadone Hydrochloride Stay in Your System: Methadone Half-Life

Updated January 10, 2025

Authored By:

Joe Gilmore

Edited By

Amy Leifeste

Medically Reviewed By

Javier Rodriguez-Winter

Authored By:

Joe Gilmore

Edited By

Amy Leifeste

Medically Reviewed By

Javier Rodriguez-Winter

Table of Contents

How Long Does Methadone Hydrochloride Stay in Your System: Methadone Half-Life

Methadone hydrochloride is a medication that’s often used to help people break free from opioid addiction. It works by reducing cravings and withdrawal symptoms, streamlining the recovery process. Methadone is a powerful drug that can stay in the body for a long time, affecting different parts of the system even after you stop taking it.

This page explains how methadone moves through the body, how long it stays in the urine, hair, and blood, and what factors make this time different for everyone. It also explores methadone’s safety, how it is regulated, and how it impacts the brain and body. You can also discover how to get evidence-based addiction treatment.

How Long Does Methadone Stay in The Urine, Blood, and Hair?

Methadone can remain in the body for varying lengths of time, depending on the test used to detect it. 

  • Urine: Urine tests are commonly used for detecting methadone because they’re easier to administer and provide accurate results. For most people, methadone can be detected in urine for 3 to 10 days. This range varies depending on overall health, length of use, and the amount of methadone in the system. Methadone has a longer half-life than many other opioids, so it remains detectable in the urine for longer [1].
  • Hair: Hair testing has the longest detection window for methadone. The drug can be detected in hair for 90 days after the last use. When methadone enters the bloodstream, tiny amounts can make their way to the hair follicles and remain trapped in the hair as it grows. Since hair tests can go back much further in time, they’re often used in cases where there’s a need to check for longer-term methadone use. Hair testing is less commonly used for methadone detection as it can be expensive and doesn’t indicate recent use as clearly as blood or urine tests. Instead, hair tests are best for determining whether someone has been using methadone for an extended period.
  • Blood: Blood tests are the most direct way to detect methadone in the body, as they measure the drug in the bloodstream. The drug can be found in the blood for about 24 hours after the last use. It may remain detectable for slightly longer in those with slower metabolisms. Blood tests are less commonly used than urine tests, especially outside of a medical emergency, because they are more invasive and expensive. Blood tests are generally used to detect methadone in a hospital setting or cases of overdose [2]. 

Half-Life of Methadone

A drug’s half-life expresses how long it takes for 50% of it to leave the system. Methadone has a long half-life of 8 to 59 hours, meaning that it stays in the body for longer than many drugs. The wide range in methadone half-life is due to differences in each person’s body and metabolism.

The long methadone half-life is one reason it’s commonly used in opioid treatment programs. Where the drug remains in the body for longer periods, it provides a steady effect, reducing withdrawal symptoms and cravings throughout the day. This slow release helps prevent the intense highs and lows associated with other opioids, allowing people to focus on recovery without feeling the urge to use drugs frequently. 

The extended half-life of methadone can be beneficial in treatment settings, but it also requires careful management. The drug can build up to high levels if doses are not carefully spaced. Medical professionals often start methadone at low doses and adjust them gradually to avoid a build-up that could lead to overdose or other complications. 

Beyond this, the long methadone half-life is useful for maintaining stable blood levels, enabling people to take the medication once daily and reduce the chances of cravings throughout the day. That said, this also means that stopping methadone use must be done gradually, as the drug will continue to affect the body even after the last dose. 

What Influences How Long Methadone Hydrochloride Stays In Your System?

Methadone doesn’t leave everybody’s system at the same rate. The following factors influence the methadone half-life:

  • Metabolism: People metabolize methadone at different rates. A person with a fast metabolism may process and clear methadone quicker than someone with a slow metabolism. Variables such as diet, activity level, and genetics can all influence someone’s metabolism.
  • Age: Older adults tend to process methadone more slowly, which can lengthen its half-life. This is often due to changes in liver function and metabolic rate that come with age [3].
  • Liver function: The liver is mainly responsible for breaking down methadone. Individuals with liver conditions may process methadone slower, extending the time it takes to leave the body. People with liver issues may need adjusted doses or extra monitoring to avoid methadone buildup.
  • Body mass: Body weight and fat distribution can also affect how long methadone stays in the system. Methadone is stored in body fat, so individuals with higher body fat may retain methadone for longer. The drug can linger in fat tissue before slowly releasing back into the bloodstream, meaning that those with more body fat may experience a delayed elimination of methadone.
  • Dosage and duration of use: Higher doses of methadone will take longer to leave the body than smaller doses. Additionally, individuals who have been taking methadone over a long period might accumulate the drug in their system, extending the detection window.
  • Other medications or substances: Certain medications or substances can slow down how quickly methadone is processed. Other drugs that affect liver function—alcohol or some prescription medications—can extend the time methadone stays in the body. When these substances are used together, they may lead to a buildup of methadone in the system, which is why doctors need to know about any substances being used alongside methadone.

Is Methadone Hydrochloride Safe?

Methadone hydrochloride is generally safe when monitored by a healthcare provider and used as prescribed. It is proven effective in treating opioid addiction—opioid use disorder—by helping people manage cravings and withdrawal symptoms. [4] Like any medication, methadone has potential risks, especially when it’s not used correctly.

Methadone has been used in treatment programs for decades because it is an effective way to help people reduce or eliminate opioid use. By reducing cravings and withdrawal symptoms, methadone can make it easier for people to stay in recovery and avoid the cycle of addiction. Additionally, because of the long methadone half-life and lasting effects, individuals often only need one dose daily, making it easier to manage. 

While methadone is safe when used as directed, it carries risks if misused. Taking more than the prescribed dose or combining methadone with other drugs can lead to dangerous side effects, including overdose. Methadone misuse may also lead to the development of dependence if people start taking it in ways that are not prescribed. This is why methadone should only be taken under close medical supervision. 

Some individuals may experience side effects when taking methadone. These may include:

  • Dizziness
  • Nausea
  • Constipation
  • Mood changes
  • Insomnia 

In rare cases, methadone may trigger serious side effects like respiratory depression, where breathing slows to dangerous levels. To ensure safety, healthcare providers usually start people on a low dose, increasing it gradually to mitigate the risk of side effects. 

People visit licensed clinics where doses of methadone are administered, and health professionals check for any signs of adverse effects. Adjustments can be made if side effects occur.

Methadone Hydrochloride Regulations

Methadone is strictly regulated. It can only be prescribed and administered in government-approved treatment facilities known as OTPs (opioid treatment programs). This regulation helps ensure that individuals taking methadone are closely supported and supervised in their recovery.

Methadone hydrochloride is classified as a Schedule II controlled substance in the United States [5]. This classification indicates that while methadone has medical uses, it also has a potential for misuse and dependence.

Daily monitoring of the drug at OTPs helps ensure that methadone is taken correctly and allows healthcare providers to monitor individuals for side effects. For those who show progress in recovery and comply with treatment guidelines, some clinics may grant take-home doses. Take-home doses afford extra flexibility, but they come with strict requirements, including regular drug screenings and check-ins with healthcare providers, ensuring that people use methadone safely outside of the clinic. 

How Methadone Affects the Brain and Body

Methadone hydrochloride affects the brain by reducing cravings and blocking the high associated with opioids. Here’s how it interacts with the brain and body:

  • Impact on brain chemistry: Methadone binds to the same receptors in the brain as other opioids like heroin, fentanyl, or prescription painkillers. By activating these mu-opioid receptors, methadone can prevent withdrawal symptoms and reduce cravings without creating the intense high triggered by other opioids. This helps people in recovery feel more stable and reduces their need to seek out other drugs.
  • Effect on the body: Methadone’s effects extend beyond the brain, impacting the whole body. The drug can slow breathing and heart rate, which is why it needs to be carefully dosed. This effect helps prevent the intense ups and downs that come with opioid use, allowing for a more controlled and gradual recovery process.
  • Long-lasting effects: Methadone is a long-acting opioid that provides steady effects over a long period, helping people avoid the sudden cravings or withdrawal symptoms that can lead to relapse. However, this also means that methadone builds up in the body over time, so missing a dose or stopping suddenly can provoke withdrawal.
  • Potential side effects: Methadone’s effects on the brain and body come with some possible side effects. Common ones include drowsiness, sweating, and digestive issues. Although rare, serious side effects can include slowed breathing, especially at higher doses.
  • Supporting recovery: By balancing the need to reduce cravings and prevent misuse, methadone offers a sustainable pathway to long-term recovery. When taken as directed, methadone enables people to focus on other aspects of their recovery, like counseling and lifestyle changes, without the constant disruption of cravings and withdrawal symptoms.

Methadone | FAQs

When does methadone peak and duration?

Methadone usually peaks in the bloodstream about 2 to 4 hours after taking it. A single dose can last anywhere from 4 to 8 hours, although effects can linger longer in some people. 

How long does methadone stay in the system?

Methadone can remain in the body for several days after use. Depending on metabolism and dose, it may be detectable in urine for 3 to 10 days. 

What is the half-life of methadone overdose?

The methadone half-life is from 8 to 59 hours – the average half-life is 24 hours. In cases of overdose, it may take even longer to clear methadone from the system. This extended half-life can increase the risk of dangerous levels building up.

Get Effective Methadone Maintenance Treatment at a Premier California Rehab

Now that you know how the methadone half-life impacts how long it stays in the system, you may feel it’s time to address opioid addiction—we can help you at California Detox. 

We treat all addictions and mental health disorders at our luxury rehab in Laguna Beach, California. The immersive nature of inpatient rehab enables you to focus on recovery fully without triggers or distractions.

Methadone maintenance therapy may be administered during detox and throughout ongoing treatment. Medication-assisted treatment is blended with therapies like: 

  • Psychotherapies like CBT and DBT
  • Motivational therapies
  • Group therapy
  • Counseling
  • Family therapy
  • Holistic treatments
  • Aftercare 

Call our friendly recovery specialists at 888-995-4208.  

Sources 

[1] https://www.ncbi.nlm.nih.gov/books/NBK310658/

[2] https://www.ucsfhealth.org/medical-tests/toxicology-screen 

[3] https://pmc.ncbi.nlm.nih.gov/articles/PMC2885886/ 

[4] https://www.ncbi.nlm.nih.gov/books/NBK562216/ 

[5] https://www.justice.gov/archive/ndic/pubs6/6096/index.htm

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