How Long Does Methadone Stay In Your System?

methadone-liquid-6Methadone is a drug used as a drug “replacement” for those who are going off drugs. Persons can intake methadone as a choice for a less dependent drug in compare to heroin. It helps with symptoms that appear after discontinuing from drug abuse and allows slow reduction of the drug effect which will allow the patient to feel better and it will stabilize its state. Methadone reacts by binding to mu-receptors and stimulates the release of beta-endorphin and enkephalin. These hormones react such that it gives the feeling of less pain (analgesia), it gives the mood change (euphoria), satisfaction and relaxation.  Some patient that intake methadone for a drug “replacement” tend to get even more addicted to the methadone than the drug they were previously on. There can be some side effects even from methadone although it is used as a drug withdrawal therapy. Some of them are dizziness, fatigue, muscle pain, digestive problems, heart issues, sedation. For those and others that want to clear the methadone out of their system, it is important to know how the whole process goes and how long does it last.

How Long Does Methadone Stay In Your System?

When you’re on methadone, it has a certain effect on your body. After its withdrawal, you can start to experience symptoms which are not quite pleasant. If you’re experiencing methadone withdrawal symptoms, you may be wondering how long does it take for the methadone to clear from your body. And this depends on many factors. The full effect of one pill that you take lasts about 8 hours, after which the methadone active ingredients can still be in your system, even if you don’t feel its action. The main parameter which follows the drug elimination time is the half-life of the medicine. For the methadone, there are a few average ranges: from 24 to 36 hours, 13 to 47 hours, 15 to 40 hours and finally 8 to 59 hours. This is an example that the half-life of methadone is different from person to person. Let’s take the shortest and the longest period of the methadone elimination and include that in the quotation. So, if the methadone elimination goes from 8 to 59 hours, 50% of clearance will occur from 1.83 days to 13.52 days. This is completely average and it depends on a person having the medicine. There are a lot of factors that can affect the clearance of the methadone.

Factors That Can Influence Methadone Clearance

Since methadone clearance is under the influence of many factors, the total elimination may vary. It depends on the individual taking the medicine, the dosage, frequency of intake, interaction with other drugs, etc.

Individual Characteristics

There are some things that are different from person to person. That kind of individual characteristics can be from age, genetics, BMI, lifestyle, etc. All of these things can influence the drug clearance from the body.


The metabolism of an old man and a younger man is different due to many things. The speed rate of the metabolism of an elderly man is much slower, therefore, the excretion of drugs will take more time than one compared to the younger body. The circulation is slower, there may be present heart problems, slower metabolism with fewer hormone levels, especially those which speed up the system. The main thing that can be different is the function of the kidneys and the liver which carry the main role in a drug excretion. If their function is disturbed, the clearance can suffer and result in a delay.

BMI Index

A person’s body mass index (BMI) depends on a person’s weight and height. The greater the mass, the bigger the index. It is linked with the amount of body mass, so the bigger the mass the longer it will take for the medicine to leave the body. Another thing which is important is the body fat. Since the methadone is a lipid-soluble drug, it tends to accumulate in the body fat. If the person has a higher percentage of fat, it is more likely that the drug will accumulate and create the fatty deposits in the lipids which can have delayed effects on the body.

Liver Function

The liver has a system made out of enzymes which break the products that help with detoxication and turns the lipid-soluble substances into a water-soluble substance which can be later on excreted through kidneys. Methadone is being detoxicated inside the liver by CYP450 enzymes (CYP3A4). If the liver function is damaged with a disease such as cirrhosis, it can reflect in a slower metabolism and excretion.


Genes regulate the enzyme and other protein synthesis, which can be different from person to person. Some individuals can have different genes which will result in longer or shorter metabolism of methadone. Genes also regulate the cytochrome P450 enzymes which act inside the liver to excrete the drug. There are persons which are called “rapid or poor metabolizer” due to a fact how long does it take for them to clear the system from certain substances, and in this case, methadone.

This is also expressed through BMR or basal metabolic rate which shows how much energy does your body need at rest. Those who have higher BMR will excrete the drug faster. Those who have low BMR will have a slower metabolism and will excrete in a slower rate.


Pregnant women have different metabolism rate than a non-pregnant woman. A pregnant woman has the faster metabolism due to different hormone levels which influence the body and will result in faster drug elimination. Research has shown that the clearance was significantly faster in 23 women in compare to 16 non-pregnant women. Another factor which will influence the methadone concentration is the plasma, where the pregnant women have a greater amount of plasma and therefore, the drug will be at a lesser concentration. The drug will leave the body quicker in pregnant women and it is less absorbed due to a faster metabolism and greater kidney flow.

Urine pH Level

Someone who has more acids in their urine will have acidic surrounding which will affect the excretion in a way that the methadone will leave the body faster. Alkaline urine will create the surrounding for a drug reabsorption prior to its excretion, leading to a higher concentration in the blood and longer clearance period.

Frequency Of Intake

Those who intake methadone in a frequent manner have more concentration in the system and therefore the drug tends to accumulate in the fat. So, when the clearance has to happen, the body has to excrete first the present methadone and then the lipid storage which has been accumulated over time. The users which take infrequently and tend to intake single-doses, they may never have the maximum levels of methadone in lipid storage and will not have accumulated levels. The “peak level” may never happen among infrequent users. Persons who intake drugs once in the day will have the whole day for excretion whereas the ones taking doses 3 times a day will have less time for excretion and there will be about half of the dose of the previous drug when taking the next one in the afternoon.


Dosage can take from 5 mg to 40 mg. The greater the dosage, the longer the time it will take for its excretion and vice versa, the smaller the dosage, the less time it will take for the methadone clearance. The dosage will also have an impact on the drug accumulation whereas those who take higher doses will accumulate more methadone in their lipid storage and will need more time to clear the system. The liver will slowly degrade the drug since there will be higher levels which can overwhelm the CYP3A4 enzymes.

Interaction With Other Drugs

When taking other drugs simultaneously with methadone, it is important to state its metabolism path. Methadone uses CYP3A4 enzymes in the liver which can be altered with the effect of another drug. Some drugs may inhibit the enzymes function which will affect the time of the methadone clearance. Such drugs can be Indinavir, Clarithromycin, Ketoconazole, Ritonavir, Nefazodone. There are also some ingredients which can alter the enzyme function such as grapefruit juice with its substance bergamottin. On the other hand, there are certain drugs which can speed up the enzyme functions. Those drugs are Rifampicin, Modafinil, Glucocorticoids, Carbamazepine, Phenobarbital.

Tips To Faster Methadone Clearance

There are a few steps which you can take to speed up the clearance of methadone. Some of them you may already figure it out from the metabolism factors which we elaborated above. All of these you should discuss with your doctor before you take any measures. This can be also relevant and may not help every person.


Considering the methadone excretion and the way it goes, it is logical that the more flow you have through your kidneys, the more urine you will excrete. Methadone gets excreted faster if you have greater flow through your kidneys. Dehydration will lead to methadone reabsorption and will result in slower elimination and longer clearance period.

Acidic Urine

If your urine has more acid in it, the urinary excretion of methadone will take less time. The more alkaline urine is, the more reabsorption will be promoted. You can acidify your urine by taking certain food and beverages such as bread with whole grain, chicken, lean beef, eggs, salads with oil and vinegar dressing, rice, noodles, pasta, prunes, plums and cranberries, cake, puddings, corn, lentils.

Body Fat

By reducing your body fat, you will prevent the accumulation of the drug in the lipid storage. If you have a higher percentage of fat, you will have more methadone residues in the system. If you eat healthily and include the food which will acidify the urine, you will speed up the methadone excretion.

CYP3A4 Inducers

CYP3A4 inducers are the substances or the drugs which stimulate the enzymes in the liver and therefore result in faster methadone excretion. It can be effective, but also dangerous, so you should consult your doctor about it and agree on a certain regimen.


If you move more, you will speed up your metabolism and it will lead to faster excretion. Doing some cardio aerobic exercise will lead to burning fat, speeding up the metabolism and faster blood flow through kidneys and liver. This has multi-beneficial properties and it will lead to shortening the methadone clearance period.


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