How long does Contrave stay in your system? (5 + factors)

In this article, we will discuss the approximate time taken by Contrave to stay in your system. We will also discuss some factors that can affect this time duration and some proper ways to ensure the safe use of this medication.

How long does Contrave stay in your system?

Bupropion/Naltrexone (Contrave) stays in your system for about 4 days. This duration is based on the half-life of Contrave. Contrave is a combination medication containing Naltrexone and Bupropion.

For Naltrexone-the half-life is almost 5 hours and the elimination half-life of Bupropion is about 21 hours. Half-life is the approximate time taken by the medication to reduce its initial concentration to half.

The remaining concentration of the drug in your system further reduces to half accordingly. This way the drug concentration continues to drop until it is completely eliminated from your body.

Contrave (Bupropion+Naltrexone) is a prescription medication used for weight management (1)

It typically takes several half-lives for a drug to be mostly eliminated from the body. So, Contrave may remain in your system for days to weeks, depending on individual factors.

However, this time duration can vary from person to person. People who are elderly or suffer from kidney or liver disease usually take longer to eliminate the drug, as compared to healthy individuals.

Factors affecting the stay time of Contrave in your body 

Several factors can influence the stay time of Contrave in your body. These include:


The higher the dose of Contrave, the longer it may stay in your system. This is because higher doses generally take longer time to be processed and eliminated. 

If you are taking a lower dose, it might leave your system more rapidly.

Individual metabolism

Each person’s metabolism is unique, and some individuals may metabolise Contrave more quickly or slowly than others. This can affect how long the medication remains in their system.

If you have a fast metabolism, you might process Contrave more quickly, leading to a shorter duration in your system. Conversely, a slower metabolism means Contrave could stay in your body for a longer time (2).

Gastric emptying time

Gastric emptying time or rate can significantly affect the stay time of Contrave or any other drug in your system. This is because the time taken by your stomach to empty its contents can either hinder or accelerate the process of adsorption.

When your gastric emptying time is delayed, this means the drug stays in your stomach for a longer period of time.


Age can impact the clearance rate of Contrave from the body. Older individuals may eliminate the medication more slowly compared to younger individuals.

Underlying health condition

Some underlying health conditions can affect the metabolism and excretion of Contrave. 

Liver performance: The liver plays a crucial role in breaking down drugs (3). If your liver is healthy and functioning well, it can efficiently metabolize Contrave, leading to a normal elimination rate. However, if you have liver issues, the drug might take longer to be cleared from your body.

Drug interactions

Certain medications or substances can interact with Contrave and affect its absorption and metabolism. Drug interactions can make your drugs more or less absorbed.

It is important to inform your healthcare provider about all the medications, supplements, or substances you are taking to avoid potential interactions.

Ensuring the safe and effective use of Contrave

The following points are important to ensure the safe and effective use of Contrave (4):

  • Always take Contrave as directed by your healthcare provider. Do not exceed the prescribed dose or duration of drug administration.
  • Ensure that Contrave is prescribed only to individuals who meet the appropriate criteria for weight management.
  • If you suspect Contrave is not working for you, do not stop it abruptly and talk to your healthcare provider.
  • If you have missed a dose, try taking it as soon as you remember. If the next dose is near, skip the missed dose and take the next one on time.
  • Keep updating your doctor about the side effects you are experiencing.
  • Inform your doctor if you are pregnant, planning to become pregnant, or breastfeeding, as the use of Contrave may need to be adjusted in these situations.
  • Combine Contrave with a weight management plan, including a healthy diet and regular physical activity.

These points are important to make sure that you are using Contrave in the best possible way. If you have any concerns about your treatment with Contrave, you should reach out to your healthcare provider for the best possible advice.


The duration of Contrave’s presence in the system can vary due to the differing elimination half-lives of its components, Naltrexone and Bupropion. Safe and effective use of Contrave involves adherence to prescribed dosages, monitoring for side effects, and ongoing medical supervision. Always consult your healthcare provider for personalised guidance and to ensure its appropriate use.


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