Complete Blood Count (CBC) Test: What It Is and Why It Is Done
This test checks whether amphetamine or methamphetamine is present in your blood sample.
{"Detects stimulant drugs in blood for monitoring or screening purposes","Used to verify proper medication use or detect drug abuse","Sample is collected via blood draw","Results are reported as positive or negative (presence only)"}
Key facts at a glance
- LOINC
- 40421-0
- Short code
- Amphet+Methamphet SerPl Ql
- Synonyms
- Amphet+Methamphet SerPl Ql
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test? A complete blood count, or CBC, is a common blood test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets, to help evaluate your overall health.
The Amphetamine/Methamphetamine test is a laboratory test that detects the presence of stimulant drugs in your blood (serum or plasma). It looks for traces of amphetamine and methamphetamine—two related stimulant substances that affect the central nervous system. The test does not measure how much of the drug is in your system, only whether it is detectable.
Why might I need this test? Your provider may order a CBC as part of a routine checkup, or to help find the cause of symptoms such as fatigue, weakness, fever, easy bruising, or unusual bleeding, and to monitor conditions like anemia or infection.
Your healthcare provider may order this test for several reasons: to monitor patients taking prescription stimulant medications (such as those for ADHD or narcolepsy) and ensure they are taking the correct dose; to screen for illegal or non-prescribed use of stimulants; as part of workplace or forensic drug testing programs; or to help diagnose suspected drug poisoning or overdose. The test helps your doctor understand your exposure to these substances.
How is the test performed? A health care professional will clean your skin, wrap a band around your upper arm, and draw a small sample of blood from a vein, usually in your arm; the sample is then sent to a laboratory for analysis.
A healthcare professional will draw a small sample of blood from a vein in your arm using a needle. The blood sample is then sent to a laboratory where it is analyzed using specialized equipment to detect the presence of amphetamine or methamphetamine. You do not need to fast or make any special preparations before this test, unless your doctor instructs otherwise.
What do the results mean? Your results show whether your red blood cell, white blood cell, and platelet counts fall within the normal range; values that are too high or too low can point to conditions such as anemia, infection, inflammation, or clotting problems, and your provider will explain what they mean for you.
Results are typically reported as either 'Positive' (drug detected) or 'Negative' (no drug detected). A positive result means amphetamine, methamphetamine, or related substances were found in your blood at the time of testing. Your doctor will interpret the result based on your medical history, medications, and the reason for testing. It is important to inform your healthcare provider about all prescription medications, over-the-counter drugs, and supplements you are taking, as some substances may affect the test results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test has important clinical applications in monitoring medication compliance for patients prescribed stimulant therapies, detecting intentional or unintentional drug overdose, and screening for substance abuse in clinical and forensic settings. Amphetamines are legitimate prescription medications used to treat conditions like attention deficit hyperactivity disorder (ADHD) and narcolepsy, while methamphetamine is a highly addictive illegal drug with severe health risks. A positive result requires careful clinical interpretation considering the patient's known prescriptions and medical circumstances. The test may also help identify drug interactions or verify that therapeutic drug levels are being maintained.
Frequently asked questions
How long do these drugs stay in my blood?
Can my prescription medication cause a positive result?
Do I need to prepare for the test?
Is the test confidential?
What happens if my test is positive?
Sources
- 1
- 2
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy