Send a saliva or blood sample, get back a "biological age". Epigenetic age tests are now sold in India too. Here is what they measure, what the most-quoted study actually found, and how to read any "reverse your age" claim.
What an epigenetic age test measures
As we age, DNA methylation changes at certain places in our DNA in fairly predictable ways. (New to methylation? Start with What is epigenetic nutrition?) Scientists built statistical models, called epigenetic clocks, that read methylation at selected sites and estimate an age from the pattern. One of the best known is the Horvath clock, published in 2013.
If your estimated age is below your calendar age, the test may describe you as "biologically younger". That is the number these tests sell.
The study everyone quotes
A 2021 pilot randomised trial is often cited as proof that biological age can be reversed. Here is what it actually did (Fitzgerald et al., 2021, Aging):
- Who: 43 healthy men aged 50–72
- What: an 8-week programme of diet, sleep, exercise and relaxation guidance, plus probiotics and plant-nutrient supplements; the control group received no intervention
- Measured with: the Horvath clock, using saliva samples
- Result: the programme group's estimated age was 3.23 years lower than the control group's at the end. Within the programme group itself, the change from the start was 1.96 years, which did not reach statistical significance.
The authors themselves wrote that larger and longer trials are needed to confirm the findings.
What that study does and does not show
- It tested a whole lifestyle programme, not a single supplement.
- It was small, short, men only, and used one clock.
- It suggests that lifestyle may move this measurement. It does not prove that any product turns back your age.
Five questions to ask before trusting a result
- Which clock was used? Different clocks are built differently and can give different answers for the same person.
- What sample? Saliva and blood contain different cell types, which can affect the estimate.
- How big is the margin of error? A change of a year or two may be within normal test-to-test variation.
- What would you do differently? If the advice is better sleep, more movement, real food and less stress, that is worth doing whatever the number says.
- Who is selling what? Be cautious when the same company sells the test and the product that claims to "fix" your result.
Where we stand
We find this research genuinely exciting, and we follow it closely. But no NEXXGENE product claims to lower your epigenetic age or reverse ageing, and we will not make that claim without strong human evidence behind it. What the evidence does support is less glamorous and more useful: consistent sleep, daily movement, managed stress, and a diet with enough protein, fibre and micronutrients, every day, for months.
That is the routine our products are designed to support, with every dose printed on the carton. (Our label promise.)
This article is for general information and is not medical advice. Epigenetic age tests are not diagnostic tests. Discuss any health test results with a qualified doctor.
