How Long Does Codeine Stay in Your System?

Codeine affects a user for a much shorter period than it can be detected. Effects of a dose of codeine are usually felt for about four to six hours.

Codeine Timeline

Codeine is a short-acting opioid. This means it will affect a user fairly quickly, and it will affect a user for less time compared to a long-acting opioid like methadone. 

Codeine is usually expected to affect an individual at a dose of 15mg to 60 mg for around four to six hours. It has a plasma half-life of three hours, which is the time it generally takes a person’s body to process half of the amount of a drug currently in their system. 

Codeine use can be detected much longer than a user will actually feel the effects of the drug. 

How Long Is Codeine Detectable?

The window to detect codeine, like any drug, will vary based on the testing method used. It should also be noted the windows discussed are general estimates. The exact amount of time any drug is detectable is affected by a variety of factors and can be difficult to predict. 

False positives are possible with any type of drug testing, although they are relatively uncommon. If you are certain the results of your test are inaccurate, talk to a healthcare provider immediately, as your window to correct the mistake will be short. In some cases, you may also need to talk with a lawyer or the organization that ordered the test, depending on what the incorrect result may mean for you.

Here is how long codeine can be detected on certain types of drug tests:

Urine Tests

Urine testing is the most common type of testing used to detect opioid use. The estimated detection window for codeine when using this type of testing is up to three days. 

Blood Tests

Blood testing isn’t very common when it comes to drug testing, as it is fairly invasive and has a comparable detection window to urine testing. However, it may sometimes be used to test a person for drug use if it is believed there is significant risk a person may try to manipulate the results of the testing, such as bringing fake “clean” urine with them to a urine test.

Saliva Tests

Saliva testing is a less common way of testing for drug use compared to urine testing, but it can have some advantages. Like blood testing, it is harder to intentionally interfere with the test, as a patient can more easily give the sample with another party present without the test being considered unduly invasive to a person’s privacy. It is also less invasive than blood testing.

The estimated detection window for saliva testing when detecting codeine use is about 36 hours. 

Hair Tests

Hair testing has one of the longest detection windows of any type of drug testing, although it takes some time for hair to show signs of drug abuse as it must first grow in. The estimated detection window for this type of testing is usually placed around 90 days, although hair from other parts of the body where hair grows slower, such as pubic or axillary hair, actually has a longer detection window (although this type of hair is almost never used). 

Because hair testing requires physically cutting some of a person’s hair, it is generally considered relatively physically invasive and avoided when possible. 

Factors That Affect Detection Times

The detection window for drug use can be affected by a variety of factors. One of the more direct ways the window can be impacted is by a person’s drug use. If a person regularly abuses codeine and/or uses heavy amounts when they do engage in codeine use, that use is usually easier to detect and for longer periods. 

One less obvious factor is a person’s ability to metabolize drugs. Some health conditions can change the way the body processes drugs. This has the potential to then keep drugs in a person’s body for longer or, less commonly, for a shorter period.  

Genetics can also sometimes impact the way a body metabolizes drugs. The same is true for certain drug interactions, with some drugs slowing down or speeding up the way the body normally metabolizes other drugs in the system.