Quick answer
In 2018, the FDA authorized the first blood test to aid in evaluating concussion in adults. It measures two proteins, UCH-L1 and GFAP, released from the brain into the blood, within 12 hours of a head injury.[1] The test is designed to help clinicians decide whether a CT scan is needed, not to diagnose a concussion on its own.[1] A rapid whole-blood version was cleared in 2024.[2]
What the tests measure
The FDA explained that the Banyan Brain Trauma Indicator “works by measuring levels of proteins, known as UCH-L1 and GFAP, that are released from the brain into blood” and that are measured within 12 hours of head injury, with results available in 3 to 4 hours.[1]
How accurate they are
In the study the FDA reviewed, which included 1,947 blood samples from adults with suspected concussion, the test “was able to predict the presence of intracranial lesions on a CT scan 97.5 percent of the time and those who did not have intracranial lesions on a CT scan 99.6 percent of the time.”[1] The FDA said the test could “rule out the need for a CT scan in at least one-third of patients who are suspected of having mTBI.”[1]
Newer tests
A plasma-based test was cleared in January 2021 and a laboratory test in March 2023.[3] In April 2024, the U.S. Army announced FDA clearance of a whole-blood rapid test that returns results in about 15 minutes and can be used up to 24 hours after injury.[2]
What a result can and can’t show
A positive result
Suggests an increased likelihood of a lesion that a CT could show, supporting the decision to scan.[1]
Because the tests were validated against CT findings,[1] they carry the same limitation as CT: a normal result does not mean no brain injury occurred. NINDS states that current blood tests and imaging can’t always detect damage from mild injuries.[4]
Timing
The tests must be drawn within a limited window after injury: within 12 hours for the 2018 test[1] and up to 24 hours for the 2024 whole-blood test.[2] People who seek care later will not have this test in their records.
Frequently asked questions
Can a blood test diagnose a concussion?
Not by itself. The FDA described the test as helping clinicians determine the need for a CT scan.[1]
What proteins do the tests measure?
UCH-L1 and GFAP.[1]
This page provides general information from the sources listed below. It is not legal or medical advice, and reading it does not create an attorney-client or provider-patient relationship. Laws vary by state and change over time. See our legal disclaimer.
Sources
- U.S. Food and Drug Administration. “FDA authorizes marketing of first blood test to aid in the evaluation of concussion in adults,” February 14, 2018. https://www.fda.gov/news-events/press-announcements/fda-authorizes-marketing-first-blood-test-aid-evaluation-concussion-adults
- U.S. Army. “Army announces FDA clearance of whole blood rapid test to help with assessment of traumatic brain injury,” April 2024. https://www.army.mil/article/274997/army_announces_fda_clearance_of_whole_blood_rapid_test_to_help_with_assessment_of_traumatic_brain_injury
- Practical Neurology. “Real-World Experience Using Biomarker Testing for the Evaluation of Acute Traumatic Brain Injury.” https://practicalneurology.com/diseases-diagnoses/tbi/real-world-experience-using-biomarker-testing-for-the-evaluation-of-acute-traumatic-brain-injury-1/32192/
- National Institute of Neurological Disorders and Stroke. “Traumatic Brain Injury (TBI).” https://www.ninds.nih.gov/health-information/disorders/traumatic-brain-injury-tbi
Sources last checked: October 11, 2026
