Last Updated:

January 30th, 2026

Methadone addiction: Signs, symptoms and side-effects

Methadone is a synthetic opioid prescribed to treat heroin and other opioid addictions. It helps ease withdrawal and supports recovery when used under medical supervision. While it can be life-changing, methadone is still a powerful drug, and dependence can develop. Recognising when treatment becomes part of the problem is vital for anyone on a methadone.

Methadone lequide in tube

What is methadone addiction?

Methadone addiction is complicated because methadone is designed to create a controlled physical dependence and replace a more dangerous drug addiction. But the difference between proper use and addiction lies in how you’re using methadone and what it’s doing to you.

If you are taking methadone as prescribed through a treatment programme, attending appointments, and your life is improving, that’s legitimate therapeutic use. But if you’re taking more than prescribed, using street methadone alongside your prescription, or have been on methadone for years with no progress toward recovery, it may be time to

How does methadone addiction develop?

Methadone addiction develops differently from other opioids because most people start taking it as treatment, not to get high. Here are the three stages:

Methadone misuse
You are in a methadone programme, and initially it works. You have stopped using heroin or other opioids, and you are in control of your life. But for some reason, you start to lose that control, taking extra methadone, using other people’s prescriptions, or stockpiling doses. Alternatively, you may have started using street methadone without ever entering treatment, treating it like any other opioid. This is rare, but methadone’s long-acting effects last longer than heroin, and in high enough doses, it can create the same feelings.
Methadone dependence
Physical dependence is expected during treatment because that’s how methadone works, but the problem is dependence beyond your prescribed dose. It is when you miss your clinic appointment and withdrawal hits within a day, when your life becomes just about your clinic visit, and when you’ve tried tapering, but can’t handle even a slight dose reduction.
Methadone addiction
This is when you have been on methadone for years with no dose reduction, when you are using street methadone on top of your prescription, or you are entirely dependent on unreliable street methadone. It is the point when methadone has become the problem it was meant to solve.

Recognising methadone addiction signs

Distinguishing between appropriate methadone maintenance and addiction can be difficult, especially in long-term treatment. No matter how long you have been using, these methadone addiction signs can show you when something’s not right:

  • Taking more methadone than prescribed or getting it from sources outside your programme.
  • Stockpiling take-home methadone doses instead of taking them as directed.
  • Craving more methadone than you need to avoid withdrawal.
  • Using other opioids, alcohol or other drugs alongside methadone.
  • Lying to programme staff to get higher doses or more take-homes.
  • Spending years in methadone treatment with no progress toward coming off it.
  • Feeling unable to function without methadone, even when you want to stop.

Young girl suffring Methadone addiction

Why is methadone addictive?

Methadone attaches to the same opioid receptors as heroin or morphine, but it stays in your system 24-36 hours. This allows for once-daily dosing, but also means that methadone levels can build up over time, and that withdrawal can be more prolonged and psychologically brutal than shorter-acting opioids.

As well as these inherent methadone effects, a range of underlying factors can increase your chances of becoming addicted:

Unsuccessful treatment
Methadone programmes create controlled dependence to help people stop taking other drugs. But if you never successfully taper off, or your medical team doesn’t plan your programme correctly, months can become years, which can become decades on methadone.
Clinic visits dominating your life
Supervised dosing means your life can become completely centred around clinic visits. This can stop you from changing jobs, moving house, or even going on holiday without a lot of complications. Missing even one day can trigger withdrawal, and the programme meant to stabilise your life can become its own form of control.
Street methadone availability
Diverted methadone from programmes has created a street market, with some people selling take-homes, obtaining prescriptions from multiple sources, or buying from others in treatment. Street methadone can be cheaper than heroin, lasts longer, and seems “safer” than unpredictable street drugs, but with inconsistent dosing and zero medical oversight, addiction risks are high.
Methadone addiction and mental health
Many entering addiction treatment are also carrying trauma, depression, anxiety, or PTSD. Methadone can help with physical dependence, but not underlying psychological pain. If that hasn’t been addressed in rehab, the symptoms are likely to come back, even if you’re using methadone.

Methadone side effects and addiction dangers

Methadone misuse carries serious risks, especially when there isn’t sufficient medical supervision or methadone is combined with other substances:

Methadone addiction and mental health
Many entering addiction treatment are also carrying trauma, depression, anxiety, or PTSD. Methadone can help with physical dependence, but not underlying psychological pain. If that hasn’t been addressed in rehab, the symptoms are likely to come back, even if you’re using methadone.
Methadone overdose and death
Like other opioids, methadone slows breathing dangerously. Because it’s long-acting, it builds up over days, so even though you feel fine at first, an overdose can happen hours after dosing. Combining methadone with benzodiazepines, alcohol, or sedatives is particularly deadly and is the main cause of methadone-related deaths. Signs of methadone overdose include nodding off, confusion, breathing that has nearly stopped, and blue-tinged lips. If you experience these, you should call 999 immediately.
QT prolongation and cardiac risks
Methadone affects your heart’s electrical system and can cause QT interval prolongation. This is a potentially fatal heart rhythm condition where the heart takes longer than normal to recharge between beats. Regular heart monitoring is essential for anyone on methadone, particularly at higher doses.
Dangerous drug interactions
Methadone interacts with many common medications, including benzodiazepines, antidepressants, certain antibiotics, and antifungals. These interactions can raise methadone levels unpredictably and cause an overdose.
Cognitive problems
Long-term methadone use can affect both short- and long-term memory, concentration, and basic decision-making. These effects can interfere with your work, relationships, and daily life, even when you’re taking methadone as prescribed.

What does methadone addiction recovery involve?

Recovering from methadone addiction is complex because methadone itself is supposed to be a treatment for addiction.

If you are in a methadone programme, speak honestly with your treatment team about reducing or stopping. They can plan a slow, medically supervised taper or possibly look at alternative medications.

If you are using street methadone, you will need to enter a formal drug detox programme first to stabilise on a consistent, known dose. This is best done at an opioid rehab centre that provides both detox and prescription drug rehab therapy as part of one programme.

After tapering off and completing therapy, ongoing support is crucial to prevent a relapse to methadone or other drugs. When researching rehab programmes, look for one that provides relapse prevention planning, aftercare, alumni services and advice on finding local support like 12-step or NA meetings.

If you don’t know where to start, we can help. Contact us today, and let’s take the first step towards recovery together.

Frequently Asked Questions

Can someone become addicted to methadone even when using it as prescribed?
Yes, methadone can cause addiction even when taken exactly as directed. People prescribed methadone for pain relief or opioid substitution therapy sometimes find their bodies adjusting to it, and feel unwell if they miss a dose. True methadone addiction develops when you keep using it to feel calm, cope with trauma or depression or other emotional reasons.
What warning signs indicate that methadone use is moving from therapeutic to addictive?
Warning signs include methadone cravings, taking more than prescribed, saving doses for later “just in case,” feeling anxious when your supply runs low, or using methadone with alcohol or other drugs to get high.
Can people feel a compulsion to increase methadone doses even without euphoria?
Yes, methadone doesn’t usually cause a strong high, but the body and brain can still crave it. As tolerance builds, some people start taking higher doses of methadone simply to avoid discomfort. That compulsion comes from dependence, not pleasure, and it’s one of the clearest indicators that there is a problem.

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