Bryan Johnson says he did not biologically age for a year. Here is what that really means

Bryan Johnson says he did not biologically age for a year. Here is what that really means

Bryan Johnson, the tech entrepreneur behind the anti-ageing “Blueprint” regimen, says he did not biologically age over a 12-month period and frames it as evidence that aggressive lifestyle, supplement and monitoring routines can slow ageing. He has also publicly linked his broader project to an “immortality by 2039” ambition, a line that circulates widely in coverage and his own social posts.

Most widely used “biological age” numbers are not a birthday-style age. They are statistical estimates built from biomarkers, commonly DNA methylation (often called epigenetic clocks) or other composite measures, intended to approximate either biological age or the pace of ageing. Tools in the DunedinPACE family, for example, are designed to estimate the rate of ageing rather than simply output a single age number.

Researchers who study epigenetic clocks and related biomarkers repeatedly flag a core limitation: these tools can be informative at a population level and for tracking directional change, but they can also be sensitive to measurement variation, lab methods, short-term physiology and model choice. That means a “flat” result over one year could reflect genuine improvement, statistical noise, or both, depending on the test and conditions.

A more rigorous way to support “I did not biologically age” would be to show consistent results across multiple independent biomarkers, repeated measurements, transparent protocols (including lab methods and error ranges), and ideally external replication. Even then, “slower ageing” would not mean “no risk”: the clinically meaningful question is whether changes translate into lower disease incidence and longer healthy lifespan over time, not just improved scores on a dashboard.

Johnson’s project sits at the intersection of real longevity science and highly personal experimentation. The science is advancing, but the leap from “my biomarkers improved” to “I’m on track for immortality by 2039” remains, at best, an aspiration rather than something current medical evidence can validate.