How Long Does Morphine Stay In Your System?

Last Updated: November 1, 2023

How long the effects of morphine last depend on several factors, including the amount of the dose, the way it was used, age, metabolism and more.

Morphine is a prescription-only opioid used to treat moderate to severe pain. The form of morphine used and how it is administered affects how quickly the body absorbs the drug and the time it takes to clear the drug from the body. Other factors, including age, health conditions and genetic background, can also contribute to how long morphine stays in your system.


Effects of Morphine

Morphine is an opioid pain medication that binds to mu-opioid receptors throughout the nervous system. It changes the way the brain and the nerves throughout the body respond to pain. Morphine is typically used to treat pain when other treatment options have failed.

Along with its pain-relieving effects, morphine may cause several unwanted side effects. Common side effects of morphine include:

  • Constipation
  • Headache
  • Dry mouth
  • Dizziness
  • Drowsiness
  • Mood changes
  • Fainting
  • Difficulty urinating
  • Stomach pain and cramps
  • Nausea
  • Vomiting
  • Decreased appetite
  • Itching
  • Hives
  • Rash
  • Trouble breathing
  • Slow heart rate
  • Low blood pressure

How Long Do the Effects of Morphine Last?

The effects of morphine depend on how it is used, the amount taken and whether someone has a tolerance from long-term use. When injected, morphine takes between 5 and 20 minutes to relieve pain. Its pain-relieving properties peak around 60 minutes and last between 3–4 hours.

It takes longer to kick in when taken as an oral solution, but its effects peak around 60 minutes after use. Its pain-relieving effects wear off after about four hours.

Morphine sulfate extended release comes in a variety of capsules and tablets that release morphine much slower than morphine sulfate oral solution. Depending on the version of extended-release morphine sulfate an individual takes, the peak effect from a single dose ranges from 2.5 hours to 10.3 hours. The time it takes for the effects of extended-release formulations also varies greatly.

Morphine Half-Life

Morphine’s half-life is between 1.3 and 6.7 hours. The half-life of a drug is how long it takes the average person to clear half of the substance from their body. Typically, it takes four to five half-lives for approximately 97% of a substance to exit the body. This means the body would eliminate morphine in about 5 to 34 hours.

How Long Does Morphine Stay In Your System?

It’s possible to no longer feel the effects of morphine but still have traces of it in your body days after use. The amount of morphine detectable in your system depends on the type of drug screening and the sample being tested.

  • Urine: Morphine exits urine relatively quickly. The urine detection window for the substance is between one and three days.
  • Blood: The plasma half-life for morphine is between 1.3–6.7 hours. This is the time it takes for the substance to be reduced by half in the blood. Traces of morphine can appear on a blood test screening for up to three days after last use.
  • Hair: Morphine remains in your hair the longest. Even as your new hair grows, the older sections of it can contain traces of the substance. It’s common for morphine to be detected in a hair follicle test up to 90 days after last use.
  • Saliva: Saliva is commonly collected by a mouth swab test. In general, saliva screenings will detect the usage of any substance within a few hours to two days after last use.
  • Breastmilk: Morphine epidural injections are commonly administered before surgery and during cesarean childbirth deliveries. One study reports the half-life of morphine in breast milk was three hours.

The amount and the way morphine is given can change when morphine levels peak in breast milk.

Factors That Affect How Long Morphine Remains in Your System

Several factors can influence how long morphine remains in your body, including:

  • Age: Older individuals may remove morphine at a slower rate than younger individuals, who have faster metabolisms.
  • Genetics: Genetics can influence a person’s biology and metabolism, impacting how fast morphine is processed by their body.
  • Body composition: The weight, height and body fat of a person can determine how quickly they can eliminate a drug from their body.
  • Kidney and liver function: Your kidney and liver play important roles in eliminating substances from your body. Poor liver and kidney function, especially damage, can often lead to longer elimination times for substances.
  • Frequency and length of use: Taking larger doses or taking morphine for a long time can increase the amount of time morphine remains in your system.

False Positives For Morphine

It’s not unusual for certain morphine tests to deliver false-positive results, which indicate that morphine is present when it actually is not. Poppy seeds found on muffins and bagels contain trace amounts of codeine and morphine. These have been known to cause false positive results in enzyme immunoassay (EIA) tests. In fact, one study found that a false-positive result occurred in a test after one poppy seed muffin or two poppy seed bagels.

Get Help For Morphine Addiction in Orlando, FL

If you or a loved one is struggling with morphine addiction, professional help is available at Orlando Recovery Center. Take the first step toward long-term recovery. Contact us today to speak with an intake coordinator.


Anderson, L. P. A. “Drug Testing FAQs”>.”, April 17, 2022. Accessed August 8, 2022. 

ARUP Laboratories. “Drug Plasma Half-Life And Urine Detectio[…]ection Window.” October 2021. Accessed August 5, 2022.

Food and Drug Administration. “MORPHINE SULFATE- morphine sulfate ca[…]d release.” April 2021. Accessed August 25, 2022.

Food and Drug Administration. “MORPHINE SULFATE- morphine sulfate in[…] solution.” February 2021. Accessed August 25, 2022.

Food and Drug Administration. “MORPHINE SULFATE- morphine sulfate so[…] solution.” March 2021. Accessed August 25, 2022.

Hallare, Jericho & Gerriets, Valerie. “Half life.””> StatPearls, June 23, 2022. August 25, 2022.

Keary, Christopher J., et al.. “Toxicologic Testing for Opiates”><spa[…]g for=”” opiates<=”” span=””></spa[…]g>: Understanding False-Positive and False-Negative Test Results.” The Primary Care Companion For CNS Disorders, July 26, 2012. Accessed August 9, 2022.

Khajuria, H., & Nayak, B. P. “Detection and accumulation of morphine i[…]using GC–MS.” Egyptian Journal of Forensic Sciences, December 2016. Accessed August 9, 2022.

Murphy, Patrick B., et al. “Morphine.””> StatPearls, June 20, 2022. Accessed August 25, 2022.

U.S. National Library of Medicine. “Morphine”>Morphine.” Drugs and Lactation Database (LactMed), April 18, 2022. Accessed August 9, 2022.

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