Opioid Testing

Why this test may be ordered

• To monitor opioid levels during medical treatment and ensure the medicine is working without dangerous amounts in your blood
• To check if you are taking the right amount of prescribed opioids and not misusing them
• As part of an overall drug testing program for employment, legal evidence, sports, or drug treatment
• If you have signs of possible opioid misuse or addiction, such as calling early for refills, constricted pupils, or withdrawal symptoms
• In an emergency room if you have signs of a possible drug overdose, such as slow shallow breathing and very low blood pressure

Preparation and collection

Tell your provider about any prescription or over-the-counter medicines you take, as some may show up as opioids on the test. Avoid foods with poppy seeds for at least three days before the test, as they can also affect results.

For a urine test, you will be given instructions for collection; in some cases a professional may need to be present. For a blood test, a small needle is used to draw blood from a vein. For a saliva test, a swab is placed inside your cheek or you spit into a tube. For a sweat test, you wear a patch on your skin for five to seven days. For a hair test, a small sample of hair is cut near the scalp.

There are no known risks to having a urine, saliva, sweat, or hair test. For a blood test, there is very little risk; you may have slight pain or bruising at the needle site, but most symptoms go away quickly.

Understanding results

Your test results depend on the type of opioid testing you had. Screening tests only show whether opioids are present in your sample; they cannot show the exact type or amount. Confirmation tests can provide more detail. Results can be affected by how fast your body uses opioids, other medicines you take, and lab methods. Always ask your provider to explain what your results mean.

• Positive (screening): Opioids were found in your sample. Limitation: Positive screening results may not be accurate (false positives). Follow-up testing is usually required to confirm the results. Next step: Your provider will likely order a confirmation test to verify the result and determine the specific opioid and amount.
• Negative (screening): No opioids were found in your sample, or a very small amount was found that is too low to be called positive. Limitation: A negative result does not rule out opioid use; you may have taken opioids that are no longer detectable in your body. Next step: Your provider will discuss the result in the context of your situation and may recommend follow-up if needed.

• Screening tests cannot show the exact type or amount of opioid present
• Positive screening results may be false positives and require confirmation testing
• Negative results do not rule out recent opioid use if the drug has already cleared from the body
• Results can be affected by how fast your body processes opioids, other medicines, and different lab methods
• At-home tests only check for presence and need follow-up lab testing for accuracy

What to do next

Ask your provider to explain what your results mean in your specific situation. If you have a positive screening result, a confirmation test is usually needed. If you are concerned about opioid use or addiction, talk with your provider about available support and treatment options.

• What type of opioid test did I have (screening or confirmation)?
• Could any medicines or foods I have taken affect my results?
• What should I do if my test result is positive?
• How often should I be tested if I am taking prescription opioids?
• Are there any resources available if I am concerned about opioid misuse or addiction?

Evidence source

U.S. National Library of Medicine: Opioid Testing