Alzheimer's blood tests are trending online. Researchers say healthy people should think twice

What happened

Researchers in Australia have raised the alarm about how Alzheimer's blood tests are being sold online. The study was published in the Journal of the American Geriatrics Society. It was reported by the Guardian on 15 September 2026. Dr Jenna Smith and colleagues at the University of Sydney looked at 188 social media posts. The posts came from Facebook, Instagram and TikTok. All of them mentioned dementia or Alzheimer's disease alongside blood tests. Between them, those accounts had a combined audience of more than 114 million followers. The team found the posts often made the tests sound simple, quick and certain. They were aimed at people who feel well and have no memory problems at all. The researchers say that is the wrong audience. A test built to help doctors work out the cause of real symptoms is being offered to healthy people as a peek into their future.

Why this matters

Dementia frightens people, and understandably so. Most of us have watched someone we love change. So a blood test that promises an early answer is very tempting. It feels like taking control. But a result you cannot act on is not control. It is worry with nowhere to go. Someone who tests positive may spend years braced for an illness that never arrives. That fear can affect sleep, mood, relationships and even decisions about work and money. There is a second problem. Because these posts reach millions of people, the idea spreads fast. When a lot of people share something, we tend to assume it must be sound. That is a normal human shortcut, and it usually serves us well. Here it does not. Popularity is not evidence. The number of likes on a post tells you nothing about what a test can measure.

What the evidence actually says

The tests look for markers in the blood called p-tau217 and p-tau181. These are proteins linked to changes in the brain that are seen in Alzheimer's disease. Finding them is genuinely useful science, and it has been a real step forward for diagnosis. But here is the part the adverts leave out. Having the marker is not the same as having the disease. A person can test positive for these biological signs and never go on to develop symptoms of dementia. The marker shows something is happening in the brain. It does not tell you whether, or when, that will turn into a problem you notice. This is why the specialists are so clear. There is global agreement among the leading neurological bodies, including the Alzheimer's Association, that these tests should not be used on healthy people who have no symptoms. They also agree the tests should never be used on their own to diagnose Alzheimer's. A result only means something when a clinician reads it alongside a proper assessment, which usually includes memory testing, a medical history and other checks. In other words, the test is a tool for a trained professional. It is not a home pregnancy test for your brain.

Qurexa perspective

We are a healthcare logistics and pharmacy delivery service in Lincolnshire. We spend a lot of our time around medicines, prescriptions and the questions people have about them. Something we see often is this: people meet a confusing health claim online, and then sit with it alone. You do not have to. A pharmacist is one of the easiest healthcare professionals in the country to speak to. You do not need an appointment, and you do not need a referral. Asking them what a test or a claim actually means costs nothing. If a question turns out to need a GP, a pharmacist will tell you that too. That is a perfectly good outcome.

Practical advice

If dementia is on your mind, here are some sensible steps. **Start with your symptoms, not a test.** If you or someone close to you has noticed real memory changes, book an appointment with your GP. That is the route that leads to help. **Be cautious about tests you can buy without a clinician.** If nobody qualified is going to explain the result, think hard about what you would do with it. **Ask three questions before any test.** What would a positive result actually mean? What would change as a result? Who will talk me through it? **Check who is speaking.** A post from a company selling the test is an advert, even when it looks like advice. Look for guidance from the NHS or from established medical bodies. **Put your energy where the evidence is strongest.** The things known to support brain health are unglamorous but real: keeping blood pressure under control, treating hearing loss, staying physically active, sleeping reasonably well, not smoking, drinking less, and staying socially connected. None of that needs a blood test. All of it is within reach.

What to know

Researchers analysed 188 social media posts, reaching a combined audience of more than 114 million followers, that promoted Alzheimer's blood tests. Many were aimed at healthy people with no symptoms. The tests detect proteins such as p-tau217 and p-tau181. A positive result shows a biological marker. It does not mean a person will develop dementia. Leading medical bodies, including the Alzheimer's Association, agree these tests should not be used on people without symptoms, and should never be used alone to make a diagnosis. If you are worried about memory changes, your GP is the right place to start. Your pharmacist is a good place to ask questions in the meantime. Sources: The Guardian, 'Researchers warn social media driving harmful misuse of Alzheimer's blood tests', 15 September 2026, https://www.theguardian.com/australia-news/2026/sep/15/researchers-warn-social-media-driving-harmful-misuse-of-alzheimers-blood-tests; Journal of the American Geriatrics Society, study led by Dr Jenna Smith, University of Sydney, 2026, https://agsjournals.onlinelibrary.wiley.com/journal/15325415; NHS, 'Dementia guide', https://www.nhs.uk/conditions/dementia/. This article is for general information and does not replace advice from a doctor, pharmacist or other qualified healthcare professional.