Bryan Johnson, the tech entrepreneur and longevity influencer, has revealed that he keeps samples of his girlfriend's menstrual blood in a -80C freezer, saying the couple is using them to study women's health. In a post on X on Thursday, Johnson shared a photo of his girlfriend, Kate Tolo, with the caption: «Kate's period blood is in my -80 °C freezer. Around 10 mL.» The disclosure has added a new and unusual chapter to Johnson's highly public campaign against ageing.
Johnson, 48, has spent years trying to become the healthiest person in the world by his own definition. He is disciplined about what he eats, takes dozens of supplements a day and tracks a vast range of biomarkers, saying he is «certainly the most biologically measured person ever». His stated ambition is to reverse his biological age and, if possible, extend his life far beyond the usual span. The latest revelation extends that project from his own body to someone else's, adding Tolo's menstrual blood to a growing collection of biological data gathered in the name of longevity research.
Tolo, who is 30, has become an increasingly visible part of Johnson's life and work. According to the couple, the frozen samples are intended to support research into female health and menstrual cycles. The explanation has been met with a mixture of curiosity and skepticism. Some observers have said that studying women's health is a worthy goal, while others have suggested that the theatrical way the announcement was made invites questions about whether the effort is primarily scientific or promotional.
The episode is not the only project linking the couple to menstrual health. Reports say Johnson has also teased the launch of a «techno tampon» designed to track Tolo's periods, a device that would fit into the couple's broader interest in collecting detailed biological data. Full details of the product have not been announced, but the idea has already drawn attention and reinforces the image of Johnson as someone willing to turn almost any bodily process into a data point.
Tolo has also been described as turning her body into a $2.6 million science experiment, with routine collection and analysis of samples and readings. The description reflects the scale of the monitoring programme around the couple and the growing tendency among biohackers to treat the human body as a system that can be measured and optimised. The reported figure has helped fuel discussion about how far personalised health research can go.
The decision to store menstrual blood at -80C is notable because of what the temperature means. Freezers set to that level are commonly used in laboratories to keep cells and other biological materials viable for long periods. By using the same conditions, Johnson is treating the samples as material for future analysis rather than as a routine waste product. The storage method is consistent with the couple's stated interest in collecting detailed health data.
The announcement has also revived debate about the ethics and presentation of biohacking. Johnson has long shared the details of his health routines online, and the menstrual blood post is the latest example of that tendency. With its matter-of-fact caption and clinical tone, the post fits a pattern in which intimate bodily information is turned into public content. Whether that pattern advances science or simply generates attention is now part of the conversation the episode has created.
