Bryan Johnson’s girlfriend is now following in his footsteps and taking on the challenge of beating the aging process.
Johnson has built a reputation for spending vast sums in an attempt to turn back his biological clock and extend his lifespan.
The investor has experimented with a wide range of methods in pursuit of staying young, including what’s been described as oxygen therapy.
He has also previously drawn attention for using blood from his teenage son in an effort to reduce his biological age, infusing himself with a litre of his son’s plasma.
Although the 48-year-old has spoken candidly about the less glamorous side of his longevity efforts, his partner, Kate Tolo, is now preparing to take on a similar project.
Sharing the update on Twitter on May 19, Johnson said Tolo is set to become “a female Bryan Johnson”.
“She will become the most measured female in history,” he said.
To do that, Tolo plans to spend $2 million per year while building a protocol designed specifically for women—something she intends to publish online at no cost.
Her first step will be dedicating the next three months to “mapping her baseline [measurement]”, which Johnson claims typically takes men just one to two weeks.
He added: “For context on the extensiveness of measurement, during the past 5 years, we’ve collected 1.5 billion data points on my body. I suspect Kate will exceed that given technology has improved since I started.
“The goal is to create a repeatable waveform of hundreds of life-critical biomarkers. Once the baseline is acquired, she will begin interventions.”
Johnson has said the pair are aiming to answer a number of questions through the project, including those outlined here:
We now have a female Bryan Johnson.
It’s Kate Tolo.
She will become the most measured female in history.
+$2 million of spend per year
+ Developing a female-specific protocol
+ Sharing everything for freeTo start, she will spend 3 months mapping her baseline. Men, in… pic.twitter.com/G9hhxjg0z1
— Bryan Johnson (@bryan_johnson) May 19, 2026
They’re also planning to examine endometriosis, a condition Tolo is suspected to have.
Johnson noted that the commitment could be a major lifestyle shift for Tolo, who he said is accustomed to “a life of freedom and spontaneity”, as she transitions into a “rigid protocol”.
“I’m proud of Kate for taking on this responsibility. It’s painful, exhausting and costly,” he further said Tolo’s upcoming journey.