What to Know About the FDA-Cleared Blood Tests for Alzheimer’s Disease

Doctors say the newest tests could help individuals who are experiencing symptoms get an earlier diagnosis

Rachel Nania,

Updated February 20, 2026

AARP

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Published May 19, 2025

/ Updated February 20, 2026

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The Food and Drug Administration (FDA) has green-lit two blood tests that can help doctors diagnose Alzheimer’s disease, which, as the most common form of dementia, affects more than 7 million older Americans and is marked by a decline in memory and thinking skills.

The tests are not screening tools, and they are not intended to provide a definitive diagnosis. However, doctors and Alzheimer’s experts say these breakthrough tests can help improve the diagnosis process and help prevent additional, unnecessary testing in people who are unlikely to have the disease.

The most recently cleared test — known as the Elecsys pTau181 test, approved in October 2025 — measures certain proteins in blood plasma associated with the disease. Its manufacturer, Roche, says it is specifically designed for the primary care setting to help doctors rule out patients who may exhibit symptoms of cognitive decline but are unlikely to have Alzheimer’s.

In May of 2025, the FDA cleared another test, called Lumipulse, which can detect abnormal clumps of protein in the brain, known as amyloid plaques. These plaques disrupt brain cell function and are a hallmark of Alzheimer’s.

PET scans and spinal fluid tests can also detect amyloid plaques and have been used for years to help doctors diagnose Alzheimer’s. But the tests are expensive and, in the case of a lumbar puncture (a.k.a. spinal tap), invasive. They can also be inaccessible for people in rural areas. Blood tests, on the other hand, require only a blood draw in patients 55 and older who are showing signs and symptoms of the disease.

“Having a blood test just makes it so much easier in being able to make a diagnosis of Alzheimer’s disease,” says Dr. Charles Bernick, a neurologist with the Cleveland Clinic Lou Ruvo Center for Brain Health, based in Las Vegas.

People without symptoms shouldn’t test

The newly approved blood tests are only meant for older adults who are experiencing symptoms of Alzheimer’s. What’s more, the FDA says that the results from blood testing should be used in conjunction with “other clinical evaluations or additional tests” to determine treatment options.

In addition to brain imaging and lumbar punctures, doctors often use neurological exams and cognitive tests, for example, to diagnose a patient with Alzheimer’s. “It still becomes a diagnosis where you have to really look at the whole picture,” Bernick says.

In recent years, the FDA has approved two medications for the treatment of Alzheimer’s — Kisunla (donanemab) and Leqembi (lecanemab). These drugs, which are given by infusion, don’t cure the disease but can help to slow the rate of decline in people in its early stages. Because they work by clearing amyloid plaques from the brain, the presence of amyloid must be confirmed before they can be prescribed.

“They carry some risk. So if you’re going to use them or utilize them, you’ve got to be pretty sure the person has that protein in the brain,” Bernick says. Risks can include swelling and bleeding in the brain.

A blood test for symptoms?

Scientists are hoping that blood tests will one day do more than help diagnose Alzheimer’s disease, but also predict when a person might start experiencing symptoms. Using blood samples from more than 600 adults, researchers analyzed a protein linked to Alzheimer’s disease and built a statistical model to predict symptom onset. The model was able to estimate how many years away a person was from developing thinking and memory problems, with an accuracy of within three to four years. The study’s findings were published in the journal Nature Medicine. For now, the researchers say, such a tool may be useful in clinical trials, since the Alzheimer’s treatments available work best when started in the earlier stages of the disease.

New test could ‘revolutionize’ research and clinical care

Some Alzheimer’s specialists have already been using blood tests not cleared by the FDA to help with a diagnosis of the disease. The FDA’s recent approvals are not required for laboratory-developed tests such as these blood tests. Having the agency’s sign-off, however, confirms a test’s accuracy and opens the door for insurance coverage and more widespread use.

Expert groups applauded the FDA’s recent approvals.

“This is another important step toward expanding access to Alzheimer’s disease diagnostic tools,” Joanne Pike, Alzheimer’s Association president and chief executive officer, said in a news release following the clearance of Roche’s new test.

“At the same time, it is important to understand this test is designed to rule out the presence of amyloid plaques,” she continued. “It is not a test that will give an Alzheimer’s disease diagnosis, nor is it a stand-alone tool for detection.”

Using the tool in a primary care setting, Pike said, can help people who might be at risk get referred to an appropriate specialist, while helping those not at risk identify what else could be causing their symptoms.

“This approach also empowers primary care clinicians to guide referrals more effectively, allowing specialists to focus on patients most likely to require advanced evaluation and care,” Pike added.

Dr. Howard Fillit, cofounder and chief science officer of the Alzheimer’s Drug Discovery Foundation, said that there’s been a “tremendous need” for blood tests and that having one will “revolutionize clinical care and clinical research” for Alzheimer’s.

“It’s going to reduce the cost of care and diagnosis, and it’s going to give people the opportunity to get a definitive diagnosis and enter into clinical trials,” Fillit told AARP in May when Lumipulse received FDA clearance.

Fillit predicted that we’ll see more blood tests in the near future, including tests that detect other key features of Alzheimer’s, such as inflammation in the brain. Having such tests could help doctors tailor a patient’s treatment as more medications come online.

“It’s kind of going to look like cancer, where patients have a tumor, there’s a biopsy of the tumor, the tumor cells are taken to the lab, they’re characterized according to various biomarkers, and then a treatment plan with various drugs in combination is designed for the patient, and the patient receives multiple drugs affecting multiple pathways in the cancer cell,” Fillit said.

“We’re going to have that for Alzheimer’s disease in the future. So this is just the beginning of really going into a new age of Alzheimer’s disease diagnosis and care and clinical trials.”

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