What gets measured
Blood panels and screens
Direct-to-consumer panels, reference ranges, and the difference between an abnormal number and a problem.
- Direct-to-consumer panels
- Reference intervals
- Measurement error
- Repeat testing
Report of the week
Your epigenetic age comes with a margin of error nobody prints
A 2026 reliability study found that DNA methylation clocks are highly reproducible in the lab and considerably less stable in the person. That distinction matters enormously.
Beat
Consumer diagnostics
Method
Read the primary study
Standard
Report the error bars
Policy
No paid coverage
What we cover
Testing moved out of the clinic and into the shop. These three sections follow what that changed: the panels, the age estimates, and the rules.
Age estimates
Biological age
Epigenetic clocks, pace-of-ageing measures, and the reliability problem underneath both.
- DNA methylation clocks
- Pace-of-ageing measures
- Test reliability
- Clinical guidelines
Rules and gaps
Oversight and access
Who is allowed to sell a test, what gets reviewed before sale, and where the gaps sit.
- Over-the-counter clearance
- Laboratory-developed tests
- Supplement regulation
- Compounded products
Recently reviewed
Each piece gets re-read when new trial data lands. Filter by section to see what changed.
Biological ageYour epigenetic age comes with a margin of error nobody prints
A 2026 reliability study found that DNA methylation clocks are highly reproducible in the lab and considerably less stable in the person. That distinction matters enormously.
Blood panels and screensSixty markers, one draw, and no idea what to do next
Direct-to-consumer panels sell breadth. Breadth without a question produces incidental abnormalities and follow-up that leads nowhere.
Oversight and accessOver-the-counter glucose sensors changed who can buy a diagnostic
A device class built for diabetes management is now a pharmacy purchase for people with no diagnosis. The clearance covers the sensor, not the interpretation.
Biological ageFive ways to measure biological age, five different answers
Methylation clocks, telomere length, blood biomarker algorithms, glycan analysis, and composite scores measure different things. Disagreement between them is expected, not anomalous.
Blood panels and screensWhat a reference range is, and why yours may not apply to you
Normal is a statistical construction built from a reference population. If you do not resemble that population, the range is a rough guide at best.
Biological ageWhat actually moves a pace-of-ageing measure
Cohort data points at the same short list every time, and none of it is available in a bottle.
What we are working on
Stories in progress, with roughly where they stand. Vote to tell the desk what to prioritise.
Publishing soon
Incidental findings from whole-body MRI screening
In review
How two labs produce different results from one sample
Drafting
Multi-cancer early detection tests and the screening trade-off
Researching
Reference intervals were built on populations that do not look like everyone
Write for us
We publish clinicians, laboratory scientists, epidemiologists, and health policy researchers. Every submission is checked against the primary source.
Test performance
Sensitivity, specificity, reference intervals, and measurement error. The unglamorous statistics that decide whether a result means anything.
Interpretation
What a clinician does with a number, and where consumer reporting of the same number diverges from that.
Regulation and access
Clearance pathways, laboratory-developed tests, direct-to-consumer rules, and enforcement.
What we will and will not publish
- Claims must trace to a named trial, review, registry entry, or regulator document.
- Pieces run 1,200 to 2,500 words and say plainly where the evidence is thin.
- No paid placements, no affiliate copy dressed as reporting, no brand-supplied claims.
- Any commercial relationship, including free product, is disclosed in the byline.
Editors' picks
Longer pieces we keep sending people back to.
Biological ageYour epigenetic age comes with a margin of error nobody prints
A 2026 reliability study found that DNA methylation clocks are highly reproducible in the lab and considerably less stable in the person. That distinction matters enormously.
Biological ageFive ways to measure biological age, five different answers
Methylation clocks, telomere length, blood biomarker algorithms, glycan analysis, and composite scores measure different things. Disagreement between them is expected, not anomalous.
Blood panels and screensRepeat testing beats one big panel
Almost every clinically useful thing a consumer test can tell you comes from the second measurement, not the first.