Are Biological Age Tests Worth Paying For?

What this means

An epigenetic clock reads DNA methylation, a pattern of chemical tags on DNA that changes with age. A formula turns that pattern into an estimated age, and the gap between that estimate and your birth date is reported as being biologically older or younger. The reasoning is that a body aging faster than its calendar age may carry more risk.

At the level of large groups, that link exists. In studies cited in a 2025 review, a 5-year increase in age acceleration was associated with an 8% to 15% higher mortality risk, and hazard ratios ranged from 1.03 to 1.87 per standard deviation of acceleration (Apsley et al., 2025). A group-level association is not the same as a reliable measurement of one person, and adding clocks to disease prediction models improved accuracy by only a few percentage points (Apsley et al., 2025).

Candidacy

Anyone can order a biological age test, and there is no medical candidacy standard for it. The reviewed research found no validated thresholds, so no group of patients has a result that tells a physician what to change (Apsley et al., 2025). People who are curious and understand the limits can use a result as a rough, low-stakes data point. It is a poor basis for starting or stopping a medication, supplement or procedure.

Clinical evaluation

A physician evaluation of healthy aging usually starts with measures that already have established cutoffs:

• Blood pressure and heart health. Readings, family history and, when appropriate, lipid testing.
• Blood sugar. Fasting glucose or HbA1c, which show coefficients of variation under 4% in the reviewed data (Apsley et al., 2025).
• Kidney function. Creatinine and related markers.
• Strength, fitness and body composition. Grip strength, walking speed, waist measurement and muscle mass where relevant.
• Sleep, medications and screening. Sleep quality, current prescriptions and age-appropriate cancer and bone screening.

These measures link to specific next steps, which is the main difference from a biological age number.

Available options

If you want to try a biological age test anyway, ask the lab four questions. Which clock does it use? What sample does it need, and is that the tissue the clock was trained on? Does it run replicates or report an error range? Has the specific test been reviewed by FDA? The tissue question matters because clocks applied to a different tissue than they were trained on can be off by roughly 20 to 30 years (Apsley et al., 2025).

Researchers are working on the reliability problem. In a 2022 Nature Aging report, retraining six clocks with a principal-component method brought most replicate pairs within 1.5 years of each other (Higgins-Chen et al., 2022). Whether a given consumer test uses that approach varies, and the lab can tell you. The other option is to skip the test and use the standard measures above.

Benefits, limitations and risks

The physical risk is small: a blood draw or saliva sample. The practical risks are false reassurance, needless worry, and spending money on products because of a number. Different clocks are trained on different targets and often disagree on the same sample, and relative age acceleration depends on which reference population is used, so the same person can look older or younger depending on the comparison (Apsley et al., 2025).

Cost is another limit. The 2025 perspective notes that research-grade clock measurements cost far more per sample than routine tests such as glucose and creatinine, and are often run in several replicates per sample (Apsley et al., 2025). Consumer prices vary by company. Ask how your sample and data are stored and shared before you send them.

What the evidence shows

What it establishes: Epigenetic clocks track with age and with mortality risk across populations. In technical replicates of the same sample, age estimates deviated by up to 9 years in some studies, and clocks showed intraclass correlation coefficients of 0.86 to 0.99 with coefficients of variation of 2% to 10% (Apsley et al., 2025). Six widely used clocks showed replicate deviations of up to 9 years before the principal-component method was applied (Higgins-Chen et al., 2022).

What it does not establish: that a result guides care, or that changing your habits moves a clock in a way that changes health outcomes for you. The authors of the 2025 perspective say clocks lack an agreed biological interpretation and remain useful for population research (Apsley et al., 2025). On regulation, FDA states that a 2024 change that placed laboratory-developed tests under device regulation was vacated by a federal court in March 2025, and that it restored the earlier regulation text on September 19, 2025 (U.S. Food and Drug Administration, 2025). That means a lab-run test may be offered without FDA premarket review, so ask what, if anything, has been reviewed.

Recovery and next steps

There is no recovery period after a biological age test, apart from a small bruise at the blood draw site. If you already have a result, bring the report to a visit along with recent lab work and a list of your medications and supplements, and ask what the number would change. Most of the time, the better question is which established measures need attention. Individual results vary.