Kate Tolo, an Australian-Bosnian marketing strategist and the girlfriend of tech venture capitalist Bryan Johnson, will spend $2 million per year to participate in a rigorous health experiment.
Rising to prominence after founding the digital payments company Braintree, which acquired Venmo before being sold to PayPal for $800 million in 2013, Johnson shifted his focus to neurotechnology and longevity, and became a self-proclaimed “biohacker.”
In 2021, Tolo joined Johnson’s brain-interface company, Kernel, and later co-founded and led the branding of his personal anti-aging brands, Blueprint, Don’t Die, and Immortals.
Five months after revealing their relationship online, in which Johnson called Tolo the “unsung hero” of his longevity projects, he shared a lengthy post on social media announcing her involvement in a customized medical research project focused on the female body.
“This is long overdue for females,” Tolo commented under Johnson’s post. “I’ll do my best to share everything: good, bad, ugly, what works, what fails. My intent is that women have someone in their court looking after their health.”
Kate Tolo’s $2 million research will allegedly make her the “most measured female in history”
On May 20, Bryan Johnson revealed that Kate Tolo will participate in a full-scale study to create “a repeatable waveform of hundreds of life-critical biomarkers” for a female-specific protocol and share their findings with the internet for free.
Introducing his girlfriend as the “female Bryan Johnson,” the entrepreneur declared that the research, which will cost $2 million per year, will make Kate Tolo “the most measured female in history.”
To begin the procedure, she will spend 3 months mapping her baseline measurements across four time points per cycle, repeating the same tasks every day. She will be studied by a full-time medical team around the clock.
“For context on the extensiveness of measurement, during the past 5 years, we’ve collected 1.5 billion data points on my body,” Johnson revealed. “I suspect Kate will exceed that, given that technology has improved since I started.”
Once the baseline measurements are acquired, Tolo will begin interventions to answer “practically useful questions” in women’s health.
Among the questions Johnson and Tolo are aiming to answer are whether fertility can be improved, perimenopause can be slowed, and premenstrual symptoms can be alleviated.
The health experiment would be a “sacrifice” for Kate Tolo
While Johnson did not say much about Tolo’s overall health status, he revealed that she likely has endometriosis. This condition affects an estimated 10% (190 million) of reproductive-age women worldwide, according to the World Health Organization.
Between her suspected condition and current lifestyle, participating in the study would be a mountainous task for Tolo, Johnson said.
“Unlike me, Kate does not have the innate desire to wake up at 4:30 am and do six hours of longevity therapies,” he wrote. “In many ways, this is a sacrifice for her. She is a creative person, going from a life of freedom and spontaneity to a rigid protocol.”
Tolo admitted she was excited but also a “little nervous” to begin the project: “This is going to be a time-intensive, willpower-intensive, and very constrictive.”
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
Previously, Johnson has experimented with several unconventional “biohacks” that netizens have labeled “useful” to “outright bizarre.”
Some of his more controversial projects include attempting to de-age his private part using Botox and shock wave therapy, ingesting 27mg of “world’s most powerful” hallucinogenic, 5-MeO-DMT, and replacing a liter of his blood with his son’s plasma.
Bryan Johnson previously shared a report on his girlfriend’s “100/100” private parts
Bryan Johnson’s latest announcement about Kate Tolo came weeks after he called her private parts the “top 1% of all vag*nas,” much to the surprise of his followers.
On April 30, Johnson took to X and shared Tolo’s “vag*nal microbiome report,” in which she had allegedly scored “100/100.” The post garnered over 21 million views.
“Her sample is dominated by the single most protective bacterial species a vag*na can host (Lactobacillus crispatus),” he explained. “Only about 25-30% of reproductive-age women globally are L. crispatus-dominant, and ‘dominant’ usually means above 50%. Kate is at 98.7%.”
He further revealed that Tolo had no Gardnerella, Candida, STIs, opportunistic pathogens, or markers of aerobic vaginitis, which indicates “lower risk of BV, UTIs, yeast infections, HPV persistence, HSV-2, and HIV acquisition, preterm birth, and improved IVF outcomes.”
While some criticized Johnson for revealing such personal details to the public, Tolo’s response made it clear she was very much on board.
“I could not be more proud,” she wrote on Instagram. “His post might seem unhinged, but oral s*x and vag*nal health aren’t talked about enough.”
“I’m grateful I have a partner who takes my health, his health, and our collective health seriously,” she concluded after detailing the risks of herpes and other s*xually transmitted diseases during oral intimacy.
“I cannot wait to learn.” The internet reacted to Kate Tolo and Bryan Johnson’s female body-specific longevity study
