Experts say a finger prick blood test could transform how Alzheimer’s is diagnosed worldwide

A simple finger prick blood test could fundamentally change how Alzheimer’s disease is diagnosed, replacing invasive and expensive procedures with a quick test carried out in GP surgeries, experts have said.

A major international trial has now begun to assess whether the new test can accurately detect the disease, raising hopes that millions of people could be spared distressing brain scans and spinal fluid tests in the future.

At present, a definitive diagnosis of Alzheimer’s requires either a specialised brain scan or an invasive lumbar puncture to analyse spinal fluid. These procedures are costly, uncomfortable and often inaccessible, particularly in early stages of the disease when symptoms may be subtle or dismissed altogether.

Researchers believe the finger prick test could mark a turning point.

If successful, the trial could not only revolutionise how Alzheimer’s is diagnosed but also help slow the disease by identifying it earlier, when treatments may have the greatest impact.

The blood test works by detecting three proteins known to be associated with Alzheimer’s. Scientists hope that measuring these biomarkers through a tiny blood sample could offer accuracy comparable to current gold standard diagnostic methods.

The large scale study, known as the Bio Hermes 002 trial, aims to enrol 1,000 participants worldwide. So far, 883 people have already joined the study, including volunteers from the UK, the United States and Canada. More than 360 participants have already completed the test.

The trial includes people with no cognitive impairment, those experiencing mild cognitive impairment, and individuals with mild to moderate Alzheimer’s disease. This broad range allows researchers to examine whether the test can detect changes across different stages of the condition.

The research is being led by medical research organisation LifeArc alongside the Global Alzheimer’s Platform Foundation, with additional support from the UK Dementia Research Institute.

LifeArc said the trial is designed to validate the finger prick method across a large and internationally diverse population, ensuring that the results are robust and reliable.

The study also follows recent breakthroughs suggesting that blood based testing could play a key role in identifying Alzheimer’s at its earliest stages, even before noticeable symptoms emerge.

Professor Henrik Zetterberg from the UK Dementia Research Institute said the new trial would directly compare the results of the blood test with existing diagnostic techniques.

“If successful, being able to diagnose Alzheimer’s with a minimally invasive, cost effective method will revolutionise diagnostics in this area and pave the way for improved diagnosis of all neurodegenerative conditions,” he said.

Experts believe earlier diagnosis could significantly alter patient outcomes. Identifying Alzheimer’s sooner could allow patients and families to plan, access support earlier and potentially benefit from emerging treatments designed to slow disease progression.

Dr Giovanna Lalli from LifeArc said progress had already been made in identifying Alzheimer’s before symptoms appear, but accessibility remained a critical challenge.

“Developing cheaper, scalable and more accessible tests is vital in the battle against this devastating condition,” she said.

The ability to diagnose Alzheimer’s in GP surgeries using a finger prick test could remove major barriers faced by patients, particularly older people or those living far from specialist centres.

Researchers caution that the trial is ongoing and results will not be final until it concludes. The study is expected to run until 2028, after which regulators will assess whether the test can be adopted more widely.

For now, scientists say the trial represents one of the most promising advances in Alzheimer’s diagnostics in years, offering hope that fear and uncertainty surrounding diagnosis may soon be replaced with speed, clarity and compassion.