Bryan Johnson's latest biohacking experiment involves a 'techno-tampon' and 14 million data points
Biohacker Bryan Johnson says his wife Kate is undergoing what he calls the most measured menstrual cycle in history.
Bryan Johnson has built a reputation on turning health tracking into spectacle, but his newest update got attention for one detail above all others: a device he described as a "techno-tampon" designed to measure arousal. Johnson said the experiment is part of an attempt to record his wife Kate's menstrual cycle in extraordinary depth, prompting both fascination and confusion online.
A cycle measured in almost every possible way
Johnson, the 49-year-old former venture capitalist known for his anti-ageing project, said Kate is now "the world's most measured woman". He has also described the cycle they are tracking as the most measured in history.
On X, he said Kate's period was due to start at any moment and that he had been waiting 34 days. He framed the moment as historic, then shared a list of what he said would be tracked across the cycle.
That list included vaginal, oral and stool microbiome recordings, along with breast measurement, urine concentration and the weighing of menstrual blood. Johnson said the project is monitoring at least 29 different aspects of Kate's health during the course of her cycle.
The detail that stood out most was his claim that Kate had been using a "techno-tampon" capable of measuring levels of arousal, which he referred to as "lady boners".
Why he says he is doing it, and why people could not stop talking about it
In a Substack post, Johnson said the aim was to gather 14 million data points on Kate's menstrual cycle. He also said the process was being overseen by a 12-person medical team.
Johnson has made stopping the ageing process and living forever a central mission, and this latest project appears to extend the same style of intensive monitoring to his wife's reproductive health.
The reaction online split in two directions. Some people praised the effort, arguing that women's reproductive and menstrual health have long been underfunded and understudied. For those users, the scale of the tracking was unusual but still worthwhile, especially because they felt this kind of research had not been given enough attention before.
Others were less sure what to make of it. Much of the confusion centred on the so-called techno-tampon itself, with users questioning how such a device would even work. Some said the whole idea sounded like something out of science fiction, even by the standards of the stranger corners of social media.
That mix of curiosity, support and disbelief is exactly what Johnson's post generated. Even for someone already known for extreme health routines, this was the update that made people stop scrolling.
What a tampon style biosensor is
A tampon style biosensor is an insertable device designed to sit in the vagina and collect biological signals. Depending on the design, it may measure things like temperature, acidity levels, moisture, blood related markers, or chemical traces in vaginal fluid. Some versions are meant to be worn briefly and removed for analysis. Others connect to a phone or external reader and turn those signals into charts, alerts, or long term trend tracking.
The main idea is simple: the vagina is a place where changes in hormones, inflammation, infection, and the menstrual cycle can show up in body chemistry. A sensor may pick up patterns earlier or more often than a clinic test, especially if someone is already tracking symptoms, periods, sleep, exercise, or fertility.
What the data can and cannot tell you
More data does not automatically mean better answers. These devices can be useful for spotting trends, such as cycle changes, unusual irritation, or shifts that might be worth discussing with a clinician. They may also appeal to people interested in fertility awareness, symptom diaries, or highly detailed self tracking.
But a consumer sensor is not the same thing as a diagnosis. Readings can be affected by lubricant, sex, menstrual blood, medications, dehydration, hygiene products, and where the device sits. The vaginal microbiome also varies from person to person and can change over time. A result that looks unusual on an app may still be normal for you, while a reassuring reading does not rule out a problem if you have pain, itching, unusual discharge, bleeding outside your normal pattern, or fever.
Practical safety points before trying one
Treat insertable trackers like any other intimate product. Use only products made for internal use, follow the instructions, and do not wear them longer than recommended. Stop using the device if it causes pain, burning, pressure, or skin irritation.
It is sensible to be extra cautious if you are pregnant, recently gave birth, have a known pelvic condition, are prone to infections, or use an internal contraceptive or medical device. Clean reusable products exactly as directed. If the product connects to an app, check what information is stored, who can access it, and whether data can be deleted.
The most useful approach is to use any readings as one piece of the puzzle, alongside symptoms and professional medical advice.
