French hospitals and medical clinics are offering a blood test to help doctors confirm or rule out an Alzheimer's disease diagnosis in patients already showing signs of cognitive decline.
The examination has been available across France in both public hospitals and private community clinics since December 2025, following its introduction around the 2025 World Alzheimer's Day initiative.
World Alzheimer's Day is marked internationally every year on 21 September to raise awareness and support research into the neurodegenerative condition. While no curative treatment exists for Alzheimer's disease, which irreversibly affects tens of millions of people worldwide, medical research has made major progress in symptom reduction and earlier diagnostic screening.
Alzheimer's disease is a progressive brain disorder that gradually destroys memory, thinking skills, and the ability to carry out simple daily tasks. It is the most common cause of dementia in older adults globally.
The disease develops in the brain through two main biological mechanisms. The first is the formation of abnormal clusters of amyloid protein, known as amyloid plaques, which compress neurons and eventually cause them to die. The second is the accumulation of another protein, called Tau, which forms tangles inside the brain cells themselves.
Diagnostic test availability and costs
The new blood test operates by measuring levels of phosphorylated tau protein at threonine 217, commonly referred to as p-tau 217 or pTau217. In medical diagnostics, a biomarker is a measurable biological indicator that signals the presence of a disease, and p-tau 217 acts as a key biomarker for brain lesions associated with Alzheimer's disease.
Among the techniques available is the Lumipulse G test, developed by the medical diagnostics manufacturer Fujirebio Diagnostics. The company obtained its first major global regulatory authorization for the test from the United States Food and Drug Administration in May 2025.
Following that international clearance, private specialized biology laboratories introduced the diagnostic guidance blood test nationwide across France. Patients can undergo the blood test in hospitals or community clinic settings for approximately 100 euros.
The examination is currently not reimbursed by France's national health insurance system, Assurance Maladie, meaning patients must cover the cost out of pocket or through private complementary insurance plans.
Strict medical guidance and eligibility
Health organizations have stressed that the blood test is not designed for general population screening. The Alzheimer Research Foundation, known in France as Fondation Recherche Alzheimer, stated on its website that the examination is not available to anyone who simply wants to test their memory or check on a family member.
The foundation explained that the blood test is strictly a diagnostic assistance tool intended for healthcare professionals. It allows clinicians to confirm or rule out an Alzheimer's disease diagnosis specifically in patients who already present symptoms of cognitive decline compatible with the disease.
Medical experts emphasize that the test is not effective at revealing amyloid plaques in asymptomatic individuals who show no clinical signs of cognitive impairment.
Because of these technical limitations, prescribing the test for patients over 50 years old is subject to strict medical regulations. Orders can only be written by a memory consultation physician, or by a specialist doctor in neurology, geriatrics, or psychiatry who has received specialized training in cognitive pathology exploration in hospital or private practice settings.
Clinical performance and traditional diagnostics
The Alzheimer Research Foundation reported that measuring p-tau 217 protein levels is currently regarded as the most effective blood biomarker for detecting brain lesions associated with Alzheimer's disease.
However, the foundation cautioned that it is not a perfect test and emphasized that results must always be interpreted in the context of a patient's overall clinical presentation. The organization added that while the blood test is a highly effective diagnostic aid for patients already experiencing cognitive impairment, it can never replace a specialized clinical evaluation.
Historically, doctors diagnosed Alzheimer's disease primarily through clinical memory assessments and cognitive examinations designed to identify severe memory loss. To obtain precise biological confirmation, medical teams relied on invasive lumbar punctures or advanced positron emission tomography scans.
A lumbar puncture, or spinal tap, requires inserting a needle between the lower vertebrae to sample cerebrospinal fluid, while a PET scan uses radioactive tracers to image metabolic activity and protein deposits in the brain. Both procedures are invasive, complex to schedule, and costly, making a standard blood draw a significantly simpler diagnostic alternative.
In France, an estimated 1.2 million people live with Alzheimer's disease or a related neurodegenerative condition. Healthcare providers across the country register approximately 225,000 new diagnoses each year.
