What are the Long-Term Effects of Methadone?

Nicole Madison
Nicole Madison

The most important long-term effect of methadone is usually the reduced craving for drugs such as heroin and morphine. Unfortunately, however, some of the long-term effects of methadone are far less pleasant. For example, a person may experience respiratory problems, such as inadequate respiration, when taking this drug for an extended period of time. Likewise, some people experience sexual changes and hormonal imbalances that are related to methadone use. Addiction is also among the long-term effects of methadone use, and people may suffer withdrawal symptoms when they stop taking it.

Heroin addicts might be treated with methadone.
Heroin addicts might be treated with methadone.

One of the long-term effects of methadone is its ability to help people fight drug additions. This drug is often used to help people overcome cravings for other drugs that are categorized as opiates, which are narcotics derived from opium. In order for this effect to be successful, a doctor usually prescribes a gradually increasing dose of methadone and carefully monitors the patient’s responses to it, and eventually, the dose is stabilized. This method of gradual introduction to higher doses of methadone is used to prevent or minimize side effects of the drug. For example, this gradual increase may help reduce the likelihood the drug will have a sedative-like effect on the patient; cause nausea, vomiting, or constipation; or affect the patient's brain function.

Withdrawal from methadone may cause vomiting.
Withdrawal from methadone may cause vomiting.

Most people who take methadone don’t experience serious health problems. In some cases, however, a person who takes this medication for a long period of time will experience problems that are related to the respiratory system. This drug may also cause hormonal changes in some patients. For example, it is sometimes associated with the reduced production of the hormone testosterone. Some women who take it may have altered menstrual cycles as well.

A person addicted to heroin may scratch excessively during the withdrawal process.
A person addicted to heroin may scratch excessively during the withdrawal process.

In some people, the long-term effects of methadone include those that are related to sexual function. Some people may experience a noticeably decreased desire for sex when they are taking it. Others may experience physical problems that prevent them from enjoying satisfactory sexual intercourse. For example, a man may become impotent as a result of methadone treatment. Such problems do not affect every person who takes this drug, however, and such side effects may depend on the dosage the individual takes.

Detoxing from methadone is as difficult as detoxing from heroin.
Detoxing from methadone is as difficult as detoxing from heroin.

Addiction is also among the long-term effects of methadone use. Though methadone is used to reduce an addict's cravings for other drugs, it is also addictive. If a person attempts to stop taking methadone after a long period of use, he is likely to suffer from withdrawal symptoms. Among these symptoms are nausea and vomiting, chills, drug cravings, and muscle cramps.

An individual may also experience excessive sweating and chills as a symptom of methadone withdrawal. Though these symptoms are unpleasant, they tend to be less severe than those one might suffer when withdrawing from drugs such as heroin. Additionally, gradually weaning the patient off methadone may help minimize withdrawal side effects.

One methadone detox method involves the use of anesthesia.
One methadone detox method involves the use of anesthesia.
Nicole Madison
Nicole Madison

Nicole’s thirst for knowledge inspired her to become a wiseGEEK writer, and she focuses primarily on topics such as homeschooling, parenting, health, science, and business. When not writing or spending time with her four children, Nicole enjoys reading, camping, and going to the beach.

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Discussion Comments


As a male who has been on Methadone for about ten years due to chronic pain, I can state with certainty that one of the side effects is the immediate onset of impotence. To put it bluntly, I went from wanting sex just about constantly for my whole adult life, to having absolutely no interest in it whatsoever. I mean none! It's kind of like what I would imagine when I heard the term 'chemical castration', (potential usage for some sex offenders?).

However, that side effect can be dealt with, with an understanding partner. (The fact that I'm 58 helps also.)

A much more serious, and understudied, side effect is the chemical effect on the brain, specifically on the memory and learning. Both these functions are negatively affected, very possibly permanently. Meaning they persist even after quitting the drug. As I said, these effects are seriously understudied, partially because of a lack of interest, (the 'who really cares about addicts' attitude found in government and the medical field in general), partially because it's a difficult thing to study.

Most of the studies that have been done has been on rats. But as a long time user, (even the use of the word 'user' has negative connotations in this context), I strongly believe that both memory and learning ability are affected, and quite negatively. It is also time related in that the longer one takes it, the worse the effects become.

More studies are certainly needed, especially since Methadone is being used much more frequently for chronic pain management these days, thereby vastly increasing the overall numbers of people who will become long time users.


People on here don't seem to know very much about methadone, so let me share some information with you all.

For starters, yes, methadone is addictive, yes you will get addicted in the same way as with heroin, and yes it has many of the same effects as heroin (except for the rush at the start when you shoot up heroin. Some one above said that they thought it might be replacing one addiction (heroin) with another addiction (methadone). That's exactly what it is! It's part of the point. You take a substance that is very similar to heroin, and it hits all the same receptors in your brain and so your body thinks you're still taking heroin, so you don't go into withdrawal. However, you have replaced one opiate with another. The reason this is allowed is that methadone doesn't give you a rush (so you don't really get a buzz of it), especially when you drink the liquid form which is used in most methadone maintenance treatment centers (MMT). The fact you don't get a buzz keeps the government and powers that be happy because they're not giving addicts a fix and keeping control of a now dependent person. By keeping the person addicted, they are dependent on their pharmacy to provide a daily dose. I've heard methadone called the liquid handcuffs. You will be just as addicted.

In fact, methadone has a longer half-life than heroin. Heroin converts to morphine in your blood stream in minutes and morphine has a half life of a few hours. Methadone has a half life of up to 60 hours, meaning that it takes longer to clear from your system. It also has high fat lipid solubility, meaning it will permeate the fat storage in your body and hang around for longer. This means that dosing methadone for addiction to heroin can be done only once a day without the highs and lows of heroin addiction, but when you try to come off methadone due to the much longer half life the withdrawal period from methadone will be much, much longer than from heroin. It won't be as intense but instead of a usual week with heroin, it can last a month or two with methadone. That's hard to cope with, so many people just continue to use for their entire life and hence the handcuff nickname.

However, don't get me wrong, though. For some people who are addicted to heroin and going down into an ever faster spiral into a pit of despair, methadone is a very good treatment and will help a person start to lead a normal life, and for a heroin addict, plain old normality can seem so distant and so great to have. So I don't want to sound like I'm against methadone treatment. Just be aware of all the info, but for many people it is a lifeline to start living life again.


@ddljohn-- My husband has been on methadone for several months and he is experiencing issues with this. In fact, he just made an appointment with his doctor to talk about this.

I think that once he's off the methadone, everything will go back to normal. Otherwise, I'm sure his doctor will recommend some kind of treatment.

So if the same happens to you, don't be surprised. It's apparently very common with methadone. It might go away after a while or may last as long as you are on the medication. Don't be embarrassed to talk to your doctor about it.


Are there any guys here who have been using methadone for a while? I was recently put on this by my doctor. I had no idea about the risk of impotence though. How likely is it? And how long after starting the medicine do these side effects begin?


I'd say that the most worrisome long term effect of methadone is definitely addiction. People must realize that when they are using methadone to get off of other drugs, they could essentially be replacing one drug with another.

The article said that the withdrawal effects of methadone is not as bad as withdrawal effects of drugs like heroin. I'm sure that's true but I also think that patients should do their best to quit methadone as long as they no longer need it. Because the longer one uses methadone and the higher the doses get, the more difficult withdrawal effects will be. The last thing anyone needs is to be addicted to yet another drug.

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