How Long Does Codeine Stay in Your System?

Codeine being poured into a spoon

Products that contain the opioid codeine are commonly prescribed for both pain and cough. If you have been prescribed codeine, you may wonder how long the drug lasts in your system. A variety of factors influence the amount of time codeine remains in your body, and understanding them is key to knowing how long you can expect codeine to stay in your system.

Duration of Effects of Codeine

Codeine is usually taken either as an oral tablet or as an oral liquid in combination with other agents. It absorbs into the body and reaches its peak about one hour after being taken. In the United States, codeine is only available as a quick-acting product. Therefore, it wears off quickly and is usually dosed every four hours for this reason. It is important to note, however, that other countries like Canada have long-acting forms of codeine as well as the quick-acting forms. If you have gotten codeine outside the United States, it might last longer for this reason.

Codeine Half-Life

The half-life of codeine depends on what is being tested. Further, because codeine has multiple breakdown products, including morphine, their half-lives should also be taken into account. In the blood, codeine’s half-life ranges from 1.4 to 3.5 hours. In saliva, the half-life ranges from 1 to 3.8 hours.

How Long Will Codeine Show in Drug Tests?

Codeine will show up in drug tests for different amounts of time depending on whether urine, blood, saliva or hair is being tested.

  • Urine: Codeine, as well as its breakdown products like morphine, show up in urine tests for about 48 hours after use.
  • Blood: Little direct data exists on how long codeine stays in the blood. However, the half-life of codeine in blood suggests that it will likely show up in blood until around 7–17 hours after use.
  • Saliva: When taken by mouth, codeine shows up in saliva drug tests about an hour after use. When injected, the drug can be found in saliva even more quickly, in as little as half an hour. Codeine continues to be present in the saliva anywhere from 7–21 hours after use.
  • Hair: Codeine starts to show up in the hair about three weeks after being used. The drug continues to stay in the hair for about ten weeks after the last use. One study showed that to prove no current codeine use, about three centimeters of hair should test negative six months after the last use.

Factors Affecting How Long Codeine Stays in Your System

Several factors can impact the length of time codeine stays in your body, such as:

  • Amount Used: The more codeine you have taken, the longer it may take for your liver to process and get rid of the drug.
  • Frequency of Use: If you use codeine frequently, it can reach a steady level in your blood in as little as 48 hours. Therefore, it may take your liver longer to get rid of the built-up codeine in your system.
  • Method of Use: If you are using long-acting codeine from outside the United States, it may take longer to leave your body than short-acting codeine from the United States.
  • Age: Older people may take longer to clear codeine from their systems than younger people, especially if they have kidney problems.
  • Overall Health: Someone in better overall health may be able to get codeine out of their body faster than someone in poor health.

False Positives for Codeine

Some substances can cause false positives for codeine when urine is being tested. These include:

How Codeine is Broken Down in the Body

Once codeine is swallowed and enters the bloodstream, the liver starts to break down the drug. Codeine has multiple breakdown products, including morphine and morphine-6-glucuronide, or M6G. When codeine has finally been processed by the liver, both the drug and its breakdown products come out in your urine.

Key Points: How Long Does Codeine Stay in Your System?

Key points about how long codeine stays in your system include:

  • Quick-acting codeine is the only product available in the United States. This form lasts a shorter time than long-acting codeine forms, which are available in some other countries.
  • Codeine can stay in your bodily fluids for up to two days in some cases and can stay in your hair for weeks.
  • Your liver needs to process codeine before your body gets rid of it, and there is no way to speed up this process.

If you or a loved one struggle with codeine or codeine-containing products, help is here. Our caring experts at Ridgefield Recovery are here to help you quit codeine for good. Contact us today to learn more.

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Verstraete, Alain. “Detection Times of Drugs of Abuse in Blood, Urine, and Oral Fluid.” The Drug Monitor, April 2004. Accessed August 3, 2019. 

Rollins, DE, et al. “Codeine Disposition in Human Hair after Single and Multiple Doses.” European Journal of Clinical Pharmacology, 1996. Accessed August 3, 2019.

Shen, M, et al. “Disappearance of 6-acetylmorphine, Morphine and Codeine from Human Scalp Hair After Discontinuation of Opiate Abuse.” Forensic Science International, April 10, 2013. Accessed August 3, 2019.

Cone, Edward, et al. “Interpretation of Oral Fluid Tests for Drugs of Abuse.” Annals of the New York Academy of Sciences, March 1, 2007. Accessed August 3, 2019.

U.S. National Library of Medicine. “Codeine Sulfate.” September 2, 2018. Accessed August 3, 2019.

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Medical Disclaimer: The Recovery Village aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.