What is Bio Age?
Your cells have their own clock
Biological age measures how old your body actually functions - not how many birthdays you've had. Right now your bio age is {bioAge} vs a chronological age of {chronoAge} - a gap of {bioAgeDelta} years. Two 40-year-olds can have bio ages of 32 and 52.
How is it measured?
DNA methylation clocks read chemical tags on your DNA. The first-generation clocks land within a few years of chronological age; the newer ones (GrimAge, DunedinPACE) are built to predict health outcomes rather than birthdays.
Explore the clocks
Tap each bio age measurement to learn more.
This step is interactive - open the Thier app to try it.
Estimate the range
How many years can bio age vary between people of the same chronological age?
This step is interactive - open the Thier app to try it.
You can move your bio age
In an 8-week pilot trial of 43 men aged 50-72 (Fitzgerald 2021), a programme of diet, exercise, sleep and relaxation changes - which also included probiotic and phytonutrient supplements - left Horvath methylation-clock age about 3 years younger than the control group. It was a small study; individual results vary, and the shift is measured by the clock, not the calendar.
8 weeks of change
See how lifestyle changes compound over 8 weeks.
This step is interactive - open the Thier app to try it.
Key Takeaway
Biological age is the most meaningful number for longevity. The goal: make your bio age consistently lower than your chronological age.