Clear answers start with understanding
Questions about memory can feel personal. A simple blood test can offer insight into changes associated with Alzheimer’s disease and help you have a more informed conversation about what comes next. [1]
The ALZ Blood Test does not diagnose Alzheimer’s on its own. Your result belongs in a conversation with a qualified healthcare provider. [5]
Understand the information, ask better questions, and decide on your next step with your provider.
The science, in plain language
Tau is a protein found in the brain. p-Tau217 is a specific form of tau that can be measured in blood. Its full name is phosphorylated tau 217; “217” identifies a particular position on the protein.
Higher blood levels are associated with Alzheimer’s-related changes, including the buildup of amyloid, another protein involved in the disease. Measuring this marker can help a clinician assess whether those changes may be present. [1]
A little background
Dementia describes problems with memory, thinking, or reasoning that interfere with everyday life. Alzheimer’s disease is the most common cause of dementia, but there are other causes.
Alzheimer’s is a progressive brain disease. Two characteristic changes are amyloid plaques, which build up between brain cells, and tau tangles, which form inside cells. These changes can begin before symptoms become noticeable. [3]
Memory concerns also have other possible explanations, including sleep problems, medication effects, depression, thyroid problems, and vitamin deficiencies. Some of these can be treated, which is one reason a broader evaluation matters. [5]
Useful insight, with clear limits
A result is most useful when you understand both what it adds and the questions it leaves open.
When questions deserve a closer look
Talk with your provider if you or someone close to you is experiencing ongoing changes such as:
These signs have several possible causes. They are reasons to seek an evaluation, rather than proof of Alzheimer’s. [4]
Understanding your report
ALZ Blood Test reports use interpretation ranges to help put the measurement in context. Follow the ranges and notes on your issued report. [10]
Negative
The measurement falls below the laboratory’s lower threshold. This suggests a lower likelihood of the Alzheimer’s-related changes assessed by the test. Ongoing symptoms still deserve follow-up.
Intermediate
The measurement falls between the laboratory’s thresholds. Your clinician may recommend additional evaluation or another type of biomarker test to clarify the result.
Positive
The measurement is above the laboratory’s upper threshold. It may support further evaluation for Alzheimer’s-related changes. It does not, on its own, establish a diagnosis or a timeline for symptoms.
Whatever the result, context matters. False positive and false negative results are possible. Your provider should consider your symptoms, medical history, and other findings when deciding what comes next. [7]
See a sample reportThe ALZ Blood Test experience
Check your ZIP code and eligibility, then complete your secure order and patient intake.
Visit an available collection location for a standard blood draw. Follow the instructions provided with your order.
Receive your results securely and review them with a qualified healthcare provider to discuss possible next steps.
Why you’re hearing about it now
A 2024 study in JAMA Neurology found that a specific p-tau217 blood assay identified Alzheimer’s-related pathology with performance comparable to cerebrospinal fluid biomarkers in the studied groups. [1]
The 2025 Alzheimer’s Association guideline describes how blood tests that meet defined performance standards can help specialists evaluate cognitive impairment. Different assays have different performance; research on one test does not automatically validate another. [2]
Explore our science & laboratory materialsQuestions, answered
Learning about testing is a good place to start.
Questions about ordering? Contact usNo. p-Tau217 testing measures a protein marker in blood. Genetic testing looks at DNA, including genes such as APOE that can influence Alzheimer’s risk. These tests answer different questions. Family history is useful to discuss with your provider. [9]
Yes. Biological changes may begin before someone notices memory or thinking problems. Detecting a marker does not tell you exactly when symptoms will begin. Research into testing people without symptoms is continuing; routine screening is not currently recommended for general clinical use. [6]
Performance depends on the specific laboratory method, thresholds, and people being tested. Results from one assay or study should not be treated as a universal accuracy rate. Your provider can help explain the evidence and limitations of the test you receive. [2]
There is currently no cure. Treatments can help manage symptoms, and some medicines can slow decline in certain people with early Alzheimer’s. Eligibility depends on a detailed medical assessment; these medicines have risks and require monitoring. A blood result alone does not determine whether a treatment is appropriate. [8]
Clarity during uncertainty
See whether the test is available in your area, and bring your questions to a qualified healthcare provider.
The evidence behind this guide
Numbered references throughout this page link to the sources below. Research and clinical guidance describe particular tests and patient populations; they do not establish the performance of every p-Tau217 test.
This guide provides general education and does not replace personalized medical advice. A qualified healthcare provider should assess whether testing is appropriate and interpret your results. Scientific understanding and clinical guidance continue to evolve.