Your True Age will never display lower than 18 years, even if you're younger or have excellent biomarkers. This is a technical limitation based on how our biological age calculations work.

Our True Age algorithm is designed to estimate biological age in adults. Setting 18 as the minimum value exists for two important reasons:

Your body isn't fully formed yet

During childhood and adolescence, your body is still developing. Metrics like Resting Heart Rate, VO2max, and lean body mass change dramatically as you grow. What's normal for a 15-year-old looks very different from what's normal for a 25-year-old.

For example, children and teenagers naturally have elevated Resting Heart Rates. This is perfectly healthy and normal. But for adults, an elevated RHR can indicate poor cardiovascular health. Our algorithm would misinterpret these natural developmental patterns as signs of accelerated aging.

Limited population data

The scientific research our algorithm is based on uses adult population data. There simply isn't enough reliable data about biological aging markers in people under 18 to make accurate calculations.

Our goal is to give you meaningful, accurate insights about your biological age. For users under 18, calculations below 18 wouldn't be reliable or useful.

If you're under 18

You can still use reThrive, but your True Age will show as 18 (the minimum value) regardless of your biomarkers. This doesn't mean your health isn't good, it just means the algorithm isn't designed to calculate biological age for developing bodies.

If you're 18 or older with excellent health

If your biomarkers indicate exceptional health, your True Age might also display as 18. This is the best possible result, showing that your biological age is as young as our algorithm can reliably measure.

You can still track your metrics and build healthy habits. As you get older and your body fully matures, your True Age calculations will become increasingly accurate and meaningful.