How Long Does Morphine Stay in Your System?

Morphine pills next to a prescription bottle and a doctors paper prescription

When someone is affected by pain that’s not responding well to other medications, they might be prescribed morphine. Morphine belongs to the opioid drug class. Although effective, morphine can be highly addictive and therefore is prescribed and monitored carefully.

Morphine can be taken orally or via an IV, and the way it’s used can affect how long it stays in your system. Different types of morphine also can last for longer periods of time, affecting the length of time that morphine stays in the body.

Duration of Effects of Morphine

The effects of morphine last between one and four hours, on average. The peak of morphine’s painkilling effect is usually felt 60 minutes after it is taken or administered, and has likely worn off after four hours. These times can vary from person to person, and the length of pain relief can depend on a person’s tolerance to the drug.

Morphine Half-Life

The average half-life of morphine, or the amount of time it takes the total starting concentration of morphine in the body to reduce to 50%, is 90 minutes. The relatively short half-life of IV-administered morphine means that it is usually provided several times per day. The half-life is much longer for extended-release tablet versions of morphine, which can have a half-life of over 20 hours.

Morphine Screening Detection Times

Morphine detection tests can be used as a safety measure for some types of employment. It can also be used to monitor or test for substance abuse. Different methods of drug tests can detect morphine use for different amounts of time and can be helpful in identifying when the drug was last used.


A positive test for morphine in urine means that the drug was used in the last two to three days. Morphine can stay in urine for longer if use has been long-term and ongoing.


Morphine is detectable in blood shortly after use, with peak concentration occurring within minutes to an hour of use. Morphine stays in the blood for a relatively short time before it is distributed or absorbed by other tissues, so it is not a commonly used detection test.


As with most drugs, morphine can be detected through saliva between a few hours to several days after use.


Drug testing through hair is used for long-term detection. Hair tests for morphine can detect use for up to 90 days

Factors Affecting How Long Morphine Stays in Your System

The length of time that morphine stays in the body is influenced by the type of morphine taken and individual, biological characteristics. For example, the half-life of extended-release morphine is over ten times longer than regular morphine and takes a much longer time to fully leave the system. The rate of metabolism of morphine also decreases with age, so it can take longer to leave the system of elderly patients. 

Key factors that can impact how long morphine stays in your system are:

  • Frequency of use
  • Age
  • Amount used
  • Overall health

False Positives for Morphine Use

False positives for morphine are rare but can still occur. Since morphine is derived from the poppy plant, eating poppy seeds before drug testing can sometimes cause a false positive for morphine. There are also reports that some types of antibiotics may cause a false positive on a morphine drug test. These results can simply be clarified by taking another test and avoiding baked goods that contain poppy seeds beforehand.

How Morphine Is Broken Down in the Body

When morphine is taken, it is distributed to different parts of the body including the muscles,  kidney, liver, intestines and brain. The majority of morphine administered is absorbed through the gastrointestinal tract

Morphine metabolism takes place in the liver, where it is broken down into smaller chemical components. The kidney is responsible for morphine excretion, and the drug is eliminated from the body through urine.

If you or a loved one is affected by a morphine addiction, The Recovery Village Ridgefield can help. Please call today to learn more about our treatment plans.

Milone, Michael C. “Laboratory testing for prescription opioids.” Journal of medical toxicology, December 2012. Accessed August 1, 2019.

Food and Drug Administration. “MORPHINE SULFATE oral solution, CII.” September, 2018. Accessed August 1, 2019. 

National Center for Biotechnology Information. “Morphine.” PubChem Database, n.d. Accessed August 1, 2019. “Drug Testing FAQs.” May 1, 2017. Accessed August 2, 2019.

Milone, Michael C. “Laboratory testing for prescription opioids.” Journal of medical toxicology: official journal of the American College of Medical Toxicology, December 1, 2012. Accessed August 2, 2019.

US Department of Transportation. “Drugs and Human Performance Fact Sheets.” National Highway Safety Administration. April 2004. Accessed August 2, 2019.

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.