p-tau217 – Early Alzheimer's Blood Biomarker
A single blood draw detects the concentration of phosphorylated Tau protein (p-tau217) in blood. Easier to obtain than a PET scan and less invasive than a lumbar puncture, it is one of the most accurate clinically validated blood markers for early Alzheimer's screening available today.
Worth testing if:
- Aged 50 or over with a first-degree relative who has Alzheimer's disease
- Subjective cognitive decline (SCD)
- Mild cognitive impairment (MCI)
- Aged 40–50 and wanting a baseline before any symptoms appear
What this test is for
A single blood draw measures the concentration of phosphorylated Tau protein (p-tau217) in your blood. Easier to obtain than a PET scan and far less invasive than a lumbar puncture, it is currently one of the most clinically validated blood markers for early Alzheimer's screening.
Alzheimer's pathology advances extremely slowly. Amyloid plaques and Tau tangles begin accumulating 15–20 years before any obvious cognitive decline appears, and that stretch of time is what medicine now regards as the critical intervention window. Until recently, detecting pathology during that window meant relying on an expensive PET scan or an invasive lumbar puncture. The p-tau217 blood test changes that — the same level of accuracy, from a single tube of blood.
Test items
1 biomarkers
Phospho-tau 217
Four steps to start your test
Order online, book a location
Choose your test and pick a blood-draw time and location that suits you as you order.
A 10-minute blood draw
When the time comes you just show up. A professional takes your sample — we handle the rest.
Accredited laboratory analysis
Samples are processed by accredited testing institutions and interpreted to standard protocols.
Digital report
Once complete, your report is uploaded to your personal account with values and reference ranges clearly marked.
Pair it with Body Decode for the full picture
This test isn't part of the core package. Build a whole-body baseline with Body Decode, then add this test on top for fuller health context
| Body Decode + this add-on | This test on its own | |
|---|---|---|
| Number of biomarkers | 68 + this test's 1 | This test's 1 only |
| Biomarkers on this page | ||
| Cross-system interpretation | ||
| Full-system integrated report | ||
| Advisor report walkthrough | ||
| Personalized action plan | ||
| 120-day check-ins |
Frequently asked questions
Dementia just happens with age — there's no need to screen for it
Dementia isn't an inevitable consequence of ageing; it is the result of pathology accumulating in the brain. Detecting it early buys the maximum possible preparation time for lifestyle intervention, medication assessment and family planning.
Only early detection lets you act during the window where it matters most.
My health check is normal and my memory is fine, so I don't need this
A routine health check cannot detect the early pathology of neurodegeneration. The whole point of p-tau217 is that it can assess risk before symptoms appear, rather than waiting until cognitive function has already declined noticeably.
p-tau217 can detect pathological change 15–20 years before symptoms appear.
What good is knowing? Alzheimer's can't be cured anyway
Knowing early means more options: lifestyle adjustment (sleep, exercise, diet), cognitive training, taking part in clinical trials, and most importantly — making personal and family plans while cognitive function is still intact.
Knowing your risk lets you prepare while you are still most able to.
Is a blood test accurate, or do I need a PET scan to be sure?
The clinically validated accuracy of p-tau217 (AUC 0.92–0.97) aligns closely with cerebrospinal fluid testing, and across several large studies it has matched the discriminative power of PET scanning — while being far simpler to obtain.
AUC 0.96 — comparable in accuracy to a PET scan.
Only older people need to worry about Alzheimer's
Alzheimer's pathology can begin accumulating as early as someone's forties. Anyone with a family history, sustained high stress, insufficient sleep or metabolic abnormalities has all the more reason to establish a baseline early and track the long-term trend.
Your forties and fifties are the best time to establish a baseline.
Does a raised p-tau217 mean I will definitely develop Alzheimer's?
A raised p-tau217 reflects signs of pathological activity in the brain — it is not a diagnosis. Results need to be read alongside clinical assessment, family history and other markers, with final guidance from a neurologist.
A raised value is a signal, not a verdict — it needs professional consultation.