Epigenetic age testing: how TruDiagnostic works

What epigenetic age testing measures

Your DNA sequence stays the same for life. How your genes are used changes, partly through small chemical tags called methyl groups that attach to specific spots on DNA (called CpG sites). This is DNA methylation. Methylation patterns change with age in predictable ways, and they are also affected by smoking, diet, stress, sleep, exercise and illness.

An epigenetic clock is an algorithm. Scientists trained it on methylation data from thousands of people, and it reads the pattern in your sample to estimate a biological age or a rate of aging.

Generations of clocks

• First generation (Horvath and Hannum clocks, 2013) were trained to predict chronological age.
• Second generation (PhenoAge in 2018, GrimAge in 2019) were trained on health markers and mortality, so they relate more closely to health risk.
• Pace-of-aging measures such as DunedinPACE (2022) estimate how fast you are aging right now. It is often described as a “speedometer” rather than an odometer. It was developed from the Dunedin Study, which tracked the same people’s health markers for decades.

How TruDiagnostic works

TruDiagnostic is an epigenetic testing laboratory in Lexington, Kentucky, founded in 2020. It is one of the best-known companies offering these tests to individuals and clinicians. According to the company:

1. Collection: you collect a few drops of blood at home with a finger prick on a dried blood spot card and mail it to the lab.
2. Analysis: the lab measures methylation at about one million DNA sites in a CLIA-certified laboratory.
3. Reports: the TruAge report includes several clocks. These include OMICmAge (developed in collaboration with Harvard researchers), DunedinPACE, and SYMPHONYAge, which estimates the aging of different body systems. Depending on the test, reports can also include a telomere-length estimate and immune cell ratios.
4. Use: tests are sold directly to individuals and through healthcare providers.

TruDiagnostic itself states that these results are intended to support, not replace, clinical judgment, and should not be the sole basis for diagnosis or treatment decisions.

Why it can be important to know

• A baseline. It gives you a starting point for a conversation with your doctor about prevention.
• Tracking change. If you change your exercise, sleep, weight or smoking, repeat testing can show whether these markers move. Use the same lab and the same test.
• Motivation. For some people, a “pace of aging” number makes prevention feel concrete.
• Checking claims. If a clinic says a stem cell or exosome treatment “reverses biological age”, ask which clock it used, before and after, in how many people, and whether health outcomes also improved.

Limits to understand

• Different clocks can give different results for the same person.
• Results vary somewhat from test to test, so small changes may be noise rather than real change.
• A clock is a predictive marker studied across large populations. It does not diagnose disease in an individual.
• A better score after a treatment does not prove that the treatment improves health or extends life.
• These tests are usually paid out of pocket. Read the company’s privacy policy before sharing genetic data.