Who Should Get a Blood Test for Alzheimer’s Disease?
The first two blood tests for Alzheimer’s disease
The first blood test for the disease, made by Fujirebio, was cleared by the FDA in May 2025. It determines the ratio of two key Alzheimer’s proteins—a form of beta amyloid and a form of tau—which reflects whether amyloid plaques are accumulating in the brain. But the test can only be run on specialized equipment and therefore isn’t widely available in commercial labs.
The second test, made by Roche and FDA-cleared in October 2025, detects levels of a version of tau that correlates with the buildup of amyloid plaques. It’s the first Alzheimer’s blood test that primary care physicians can prescribe to rule out the disease.
The newest Alzheimer’s blood tests
The latest two tests, cleared in August, are intended to make diagnosing Alzheimer’s disease easier and more accurate.
PrecivityAD2, a new blood test from the diagnostics company C2N, is based on an earlier version of the company’s test that was available only via certified labs. It uses a technology called mass spectrometry that is a more sophisticated way of picking up amyloid and tau compared to traditional assays. It provides a probability score that reflects how likely a person is to have amyloid plaques in the brain. Major laboratories as well as specific clinic and health system labs are able to perform it, so it is more widely available for doctors to prescribe.
