FDA Clears First Alzheimer Blood Test for Adults as Young as 40

The FDA has cleared a blood test, PrecivityAD2, which was developed and validated by C2N Diagnostics to help diagnose Alzheimer disease.^1,2 It performs comparably to more invasive methods such as spinal taps and brain scans, offering clinicians a less invasive approach for evaluating amyloid pathology.²

Approximately 7.2 million Americans age 65 and older currently live with Alzheimer disease, and the number is projected to potentially increase to 13.8 million by 2060, according to the 2025 Alzheimer’s Disease Facts and Figures report.³ PrecivityAD2 is the first test developed and approved for adults 40 years and older who present with signs or symptoms of cognitive impairment.¹

“Every advance that helps people get an accurate Alzheimer’s diagnosis earlier matters,” said Joanne Pike, DrPH, Alzheimer’s Association president and CEO.

Less Invasive Method: Single Blood Draw

The blood-based biomarker test is intended to be used alongside a clinical assessment to aid health care professionals experienced in evaluating cognitive impairment to identify amyloid pathology associated with the disease. The biomarker test is not meant to be used as a stand-alone diagnostic and can identify amyloid pathology based on a single blood draw.² Extending clearance to adults as young as 40 recognizes that younger-onset Alzheimer disease is a reality for many families and can help affected adults acquire personal health information and access to care planning options sooner, Pike said.

“The PrecivityAD2 test provides an accurate and reliable way to detect the presence of brain amyloid plaques associated with Alzheimer’s disease pathology based on a single blood draw,” said Randall J. Bateman, MD, WashU Medicine, codeveloper of the underlying research. “With FDA clearance, this innovation can reach more patients, increasing early and accurate diagnoses for people who are seeking causes of cognitive symptoms such as memory loss. With faster diagnosis, patients can receive earlier treatment, when treatments are most effective.”

Shifting Alzheimer Diagnostic Landscape

The clearance follows additional research presented at the Alzheimer’s Association International Conference (AAIC) 2026 on the growing evidence base for blood-based biomarker tests in diagnosing Alzheimer disease.^4,5 One study of 1310 patients with mild cognitive impairment or dementia, evaluated by 165 physicians, found that primary care clinicians’ diagnostic accuracy rose from 65% to 93% after reviewing results from the PrecivityAD2 blood test, matching the roughly 90% accuracy achieved by specialists.⁴

A separate study following nearly 2700 cognitively unimpaired adults found that those with elevated levels of p-tau217, a protein associated with Alzheimer disease pathology and detectable years before symptoms appear, faced a 78% estimated risk of cognitive impairment within 10 years.⁵

PrecivityAD2 marks the third blood-based biomarker test for Alzheimer disease cleared by the FDA in just over a year, a pace that reflects how quickly the diagnostic landscape has shifted.⁶

“Today’s clearance reflects how rapidly the field is advancing. Just over a year ago, there were no FDA-cleared blood tests for Alzheimer’s and now we have 3,” said Isobel Coleman, CEO of the Alzheimer’s Drug Discovery Foundation.

PrecivityAD2 Remains One Piece of the Diagnostic Workup

Despite the advance, no single stand-alone test can definitively diagnose Alzheimer disease. Blood-based biomarker testing is intended to function as 1 component of a broader diagnostic workup, and physicians are expected to combine results with a patient’s medical history, a neurological exam, cognitive assessments, brain imaging, and, where appropriate, spinal fluid analysis before reaching a diagnosis.¹

“PrecivityAD2 reflects how far biomarker science has come, and it points to an even bigger opportunity ahead,” said Laura Nisenbaum, PhD, interim chief science officer at the Alzheimer’s Drug Discovery Foundation.⁶

References

1. Alzheimer’s Association statement on FDA clearance of PrecivityAD2 blood test for Alzheimer’s diagnosis in adults as young as 40. News release. Alzheimer’s Association. August 20, 2026. Accessed September 2, 2026. https://www.alz.org/news/2026/fda-clearance-precivityad2-blood-test-alzheimers
2. Washington University School of Medicine. FDA clears blood test to aid evaluation for Alzheimer’s disease. News release. WashU Medicine. August 21, 2026. Accessed September 2, 2026. https://medicine.washu.edu/news/fda-clears-blood-test-to-aid-evaluation-for-alzheimers-disease/
3. Alzheimer’s Association. 2025 Alzheimer’s disease facts and figures. Alzheimers Dement. 2025;21(4):e70235. doi:10.1002/alz.70235
4. Blood test improves diagnostic accuracy for Alzheimer’s in primary care. News release. Alzheimer’s Association. July 14, 2026. Accessed September 2, 2026. https://aaic.alz.org/releases-2026/alzheimers-blood-test-accurate-diagnosis-pcp.asp
5. Blood test predicts Alzheimer’s risk a decade early. News release. Alzheimer’s Association. July 15, 2026. Accessed September 2, 2026. https://aaic.alz.org/releases-2026/blood-test-p-tau217-predicts-alzheimers-risk.asp
6. FDA clearance of C2N Diagnostics’ PrecivityAD2 blood test advances precision medicine for Alzheimer’s, building on groundwork laid by early ADDF investment. News release. Alzheimer’s Drug Discovery Foundation. August 20, 2026. Accessed September 2, 2026. https://www.alzdiscovery.org/news-room/announcements/fda-clearance-of-c2n-diagnostics-precivityad2-blood-test-advances-precision-medicine-for-alzheimers-building-on-groundwork-laid-by-early-addf-investment