Bryan Johnson and Kate Tolo have announced an intensive 100-day women’s health project that will combine menstrual blood analysis, wearable monitoring and extensive biomarker tracking, although no peer-reviewed findings have yet been reported.
Millionaire longevity entrepreneur Bryan Johnson and his partner, Kate Tolo, have announced a $2.6 million women’s health project centered on extensive menstrual-cycle monitoring and the analysis of menstrual blood.
Johnson said that approximately 10 millilitres of Tolo’s menstrual blood had been stored in a laboratory-grade freezer at minus 80 degrees Celsius. The sample is expected to be analysed for cellular signals, possible disease-related tissue and environmental exposures.
The project is ambitious, heavily instrumented and designed around one participant. For that reason, it should be understood as an intensive self-tracking research effort rather than evidence of a clinically proven diagnostic test or treatment.(1✔ ✔Trusted Source
Bryan Johnson’s New $2.6M Women’s Health Project
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Why Menstrual Blood Is Central to the Project
Johnson described menstrual blood as valuable but underused in health research. Unlike a standard blood draw, menstrual effluent can contain material shed from the uterine lining, along with immune cells, stromal cells and other biological components that may reflect changes inside the reproductive tract.(1✔ ✔Trusted Source
Bryan Johnson’s New $2.6M Women’s Health Project
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The project intends to examine the sample for possible disease-associated tissue and to measure microplastics, per- and polyfluoroalkyl substances, commonly called PFAS, and chemicals that may interfere with hormonal signalling.
This approach is attractive because menstrual blood can be collected repeatedly without surgery. However, obtaining a biological sample non-invasively does not automatically make a test clinically accurate. Collection methods, contamination control, laboratory procedures and interpretation thresholds all require validation.
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Inside the 100-Day Women’s Health Project
Tolo says she plans to measure about 1,900 biomarkers over 100 days. Project organizers also say the programme will use more than 50 monitoring devices, involve over 100 daily tasks and generate approximately 14 million data points under the supervision of a 12-person medical team.
The routine is expected to track menstrual-cycle changes alongside sleep, temperature, activity, hormones, metabolic measures and other physiological signals. The project also refers to an experimental technology-enabled tampon intended to support menstrual data collection.
The reported $2.6 million cost is an estimate from the project organizers. Detailed information about the budget, laboratory methods, study protocol, ethics oversight, data governance and statistical analysis has not yet been made publicly available in a peer-reviewed publication.
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Kate Tolo Opens Up About Endometriosis, PCOS and Adenomyosis
Tolo has publicly said that she lives with endometriosis, polycystic ovary syndrome (PCOS) and adenomyosis. These conditions can affect menstrual cycles, pain, fertility, metabolic health and quality of life, but they are biologically distinct and may require different diagnostic and treatment strategies.
Endometriosis occurs when tissue similar to the lining of the uterus grows outside the uterus. The World Health Organization estimates that it affects about 10% of women of reproductive age worldwide. Diagnosis is often delayed, with WHO reporting an average interval of approximately four to 12 years.(2✔ ✔Trusted Source
https://www.who.int/news-room/fact-sheets/detail/endometriosis
PCOS is a common hormonal and metabolic disorder that can affect ovulation and menstrual regularity. Adenomyosis occurs when tissue from the uterine lining grows into the muscular wall of the uterus and may contribute to heavy bleeding and pelvic pain.(3✔ ✔Trusted Source
Polycystic ovary syndrome
Johnson Says Tolo’s Endometriosis Was Identified in 42 Days
Johnson has said that his team identified Tolo’s endometriosis within 42 days using ultrasound, magnetic resonance imaging and blood testing rather than surgery. This is an account of one person’s diagnostic process and has not been presented as a peer-reviewed clinical study.
WHO notes that ultrasound and other imaging techniques can support the diagnosis of endometriosis, while surgery may still be necessary in some cases. The appropriate pathway depends on symptoms, disease location, available expertise and clinical judgement.
A faster individual diagnosis is encouraging, but it does not establish that the same combination of tests will deliver equal accuracy across a wider population.
Research Explores Menstrual Blood for Endometriosis Detection
Scientific interest in menstrual effluent is growing independently of Johnson and Tolo’s project. Researchers are studying whether its cells, proteins, inflammatory signals, lipids, genetic markers and epigenetic patterns could help identify endometriosis or other reproductive-health conditions.
A 2025 study described a menstrual blood-based platform that combined genetic and inflammatory markers to investigate non-invasive endometriosis detection. Other pilot studies have reported differences in immune-cell populations, cytokines, gene expression and lipid profiles between participants with and without endometriosis.
A 2026 systematic review concluded that menstrual effluent has meaningful diagnostic potential, while also identifying important barriers such as inconsistent collection methods, small study populations, variation across menstrual cycles and the need for independent external validation.
These findings support further research. They do not yet mean that menstrual blood testing can replace established clinical assessment, specialist imaging or surgery when surgery is medically indicated.
Clinical Evidence Will Determine the Project’s Medical Impact
Johnson and Tolo’s 100-day initiative may generate an unusually detailed dataset on menstrual and reproductive health, but it remains a single-participant personal research project rather than a clinical trial.
Johnson has also spoken about using AI and biotechnology to address his autoimmune atrophic gastritis and Tolo’s endometriosis; however, these remain research ambitions rather than demonstrated medical outcomes.
What Happens After the 100 Days
Johnson and Tolo say the first 100 days are intended to establish a detailed baseline. They plan to test interventions only after that phase and have promised to publish results, including findings that do not support their expectations.
For clinicians and researchers, the key questions will be whether the measurements are analytically reliable, whether changes are clinically meaningful and whether the findings can be reproduced in larger, independent studies.
Menstrual blood may become a useful source of reproductive-health information. This project could add data to that emerging field, but its claims will need to move from personal experimentation to rigorous clinical evidence before changing diagnosis or treatment.
References:
- Bryan Johnson’s New $2.6M Women’s Health Project- ( https://www.healthandme.com/health-news/bryan-johnsons-new-2-6m-womens-health-project-centers-on-girlfriends-menstrual-blood-article-155223852)
- Endometriosis- (https://www.who.int/news-room/fact-sheets/detail/endometriosis)
- Polycystic ovary syndrome- (https://www.who.int/news-room/fact-sheets/detail/polycystic-ovary-syndrome)
Source-Medindia