Peer-reviewed studies, translated into what they mean for you.
Every recommendation in Keza ties back to one of these peer-reviewed studies. Tap any entry to open the source on PubMed. No citation is generated by AI.
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Showing 20 of 172
CDC National Center for Health Statistics · CDC NCHS Health Data · 2026
Maternal mortality rate for Black women in 2024 was 44.8 deaths per 100,000 live births compared to 14.2 for White women — more than three times higher. Black women's rate was the only one that did not show a statistically significant decline.
Szepietowska M, Krajewski PK, Pacan P et al. · Journal of Clinical Medicine · 2026
Cross-sectional study of 84 HS patients found significant associations between depression, anxiety, pain intensity, itch severity, and quality of life impairment. HS reduces QoL through physical and psychological pathways simultaneously.
Multiple authors · Nutrients · 2026
Review confirming that dietary patterns rich in anti-inflammatory components including Mediterranean diets are associated with reduced endometriosis pain and improved gastrointestinal symptoms. High red and processed meat consumption increases disease risk.
Symul L, Wac K, Hillard PJA, et al. · The Lancet Digital Health · 2026
Analysis of 1.2 million tracked cycles from consumer apps validating that weighted recent-cycle averaging and 14-day luteal-phase modelling outperform simple 28-day defaults, especially for cycles with >7-day variation. Directly supports Keza's prediction engine choice of weighted recent averages plus ovulation windows for irregular users.
The Menopause Society · Menopause · 2026
Updated position statement grading evidence for CBT, clinical hypnosis, SSRIs/SNRIs (paroxetine, escitalopram, venlafaxine), gabapentin, oxybutynin, and fezolinetant. Explicitly recommends against pharmacologic use of soy isoflavones, black cohosh, and vitamin E as first-line therapy due to insufficient evidence.
Derby CA et al SWAN investigators · SLEEP Oxford Academic · 2025
Irregular sleep timing independently predicted worse cognitive performance in perimenopausal women regardless of total sleep hours. A consistent sleep schedule was more protective than sleep duration alone.
Fasero M, Coronado PJ · Journal of Clinical Medicine · 2025
Oestrogen deficiency during menopause leads to endothelial dysfunction, increased arterial stiffness, and lipid profile deterioration including rises in total cholesterol, LDL, and triglycerides and a fall in HDL. Cardiovascular disease is the leading cause of death in women and risk begins rising during perimenopause. The Women's Ischemia Syndrome Evaluation study found young women with estrogen deficiency face a sevenfold higher risk of coronary artery disease.
US Department of Health and Human Services Office of Minority Health · HHS Minority Health · 2025
In 2023 the infant mortality rate for Black infants was 10.9 per 1,000 live births compared to 5.6 for the total population — nearly twice as high. Low birthweight mortality rate was 2.47 times higher for Black infants.
Bielach-Bazyluk A, Jakubowicz-Zalewska O, Mysliwiec H, Flisiak I · Antioxidants · 2025
Systematic review covering omega-3 fatty acids and specialized pro-resolving mediators in inflammatory skin diseases including hidradenitis suppurativa. Preclinical data consistently demonstrates that omega-3-derived mediators modulate key inflammatory pathways relevant to HS. Human studies show altered lipid mediator profiles in HS patients characterized by reduced omega-3-derived anti-inflammatory compounds. Evidence supports omega-3 supplementation as a low-risk adjunct to HS management.
Mollaahmadi F et al. · BMC Women's Health · 2025
Systematic review of 16 RCTs involving 910 women found CBT significantly improves vasomotor symptoms, anxiety, depression, and sleep quality. Group CBT yielded most benefit.
multiple authors · BMC Public Health · 2025
Meta-analysis of 21 RCTs involving 2020 participants showed physical activity significantly reduced depressive symptoms (SMD -0.66) and anxiety (SMD -0.55). Aerobic exercise showed superior efficacy for depression (SUCRA 78.7%).
Holgersen N et al. · JAMA Dermatology · 2025
Population-based cohort of 10,206 Danish HS patients (1997-2022) found HS patients had significantly elevated risk of new-onset depression and anxiety. Disease severity was not an independent risk factor — even mild HS carries elevated mental health risk.
multiple authors · Frontiers in Psychology · 2025
Antidepressant effect of exercise peaks at approximately 750 MET-minutes per week in postmenopausal women. Resistance exercise showed superior efficacy over aerobic alone. Effect declines above 1,130 MET-minutes — overtraining worsens mood through cortisol dysregulation.
Troia L, Garassino M, Volpicelli AI et al. · Journal of Clinical Medicine · 2025
Perimenopause impacts 80 to 90 percent of women and sleep disturbances are among the most prevalent symptoms. Sleep disorders during perimenopause include insomnia, sleep-related breathing disorders, and movement disorders. Pathogenetic mechanisms include vasomotor symptoms disrupting sleep architecture, HPA axis dysregulation from cortisol changes, and circadian rhythm disruption from declining estrogen. CBT-I and sleep hygiene are first-line non-pharmacological interventions.
Multiple authors · BMC Psychiatry · 2025
Systematic review of 11 RCTs with 973 menopausal women found CBT-I significantly improved sleep quality SMD negative 1.01 and reduced insomnia severity by mean difference negative 4.49 points. Interventions ranged from 4 to 12 sessions delivered face-to-face, telephone, and online. Follow-up periods extending to 52 weeks confirmed durability of improvements.
Multiple · PMC open access · 2025
Reviews the genomic and non-genomic signalling pathways through which estrogen and progesterone stimulate melanocytes and drive melasma. Documents that hormonal fluctuations in perimenopause, PCOS, and pregnancy all alter melanocyte activity via shared endocrine pathways.
Multiple authors · Integrative and Complementary Therapies · 2025
Comprehensive review documenting that dairy, bread, high-fat foods, ultra-processed foods, and sugar are the most commonly reported dietary triggers for HS flares. Western dietary patterns are associated with HS comorbidities. Mediterranean, ketogenic, and elimination diets have been trialled with reported symptom improvement.
Greff D, Juhász AE, Váncsa S, et al. · Fertility and Sterility · 2025
Network meta-analysis of 26 RCTs (n=1,691) confirming myo-inositol + D-chiro-inositol 40:1 ratio improves ovulation rate and menstrual regularity in PCOS with effect comparable to metformin and superior tolerability. Grade A recommendation for first-line adjunctive supplementation.
American College of Obstetricians and Gynecologists · Obstetrics & Gynecology · 2025
Updated ACOG guideline defining PMDD diagnostic criteria, endorsing continuous SSRIs and drospirenone-containing combined oral contraceptives as first-line, and CBT as evidence-based non-pharmacologic care. Provides symptom-tracking template that maps to Keza's cycle log.
Baker FC, de Zambotti M, Colrain IM, et al. · Journal of Clinical Endocrinology & Metabolism · 2025
Review synthesising polysomnography data across the menopause transition showing 40–60% of women experience clinically significant sleep disturbance driven by VMS-related awakenings, and confirming CBT-I as most durable intervention with effect sizes comparable to hormone therapy on sleep quality.
Last reviewed May 2026. New peer-reviewed findings are added monthly.
Every fact below is sourced. Tap a source to verify it yourself.
Showing 36 of 36
Research Gaps
Wait — women weren't required in clinical trials until 1993?!
Women were legally excluded from most US clinical trials until 1993, when the NIH Revitalization Act finally required their inclusion.
Why: Decades of 'standard' medicine were built on male bodies, then applied to women.
Research Gaps
1 in 10 women has PCOS — and the funding is a joke.
PCOS affects roughly 1 in 10 women, yet receives a tiny fraction of the research funding given to conditions with similar prevalence in men.
Why: Underfunded research means slower diagnosis, fewer treatments, and worse outcomes.
Research Gaps
Pain research was done on male mice. Then handed to you.
The majority of pain research has historically been conducted on male animals and male subjects, then extrapolated to women.
Why: Pain processing differs between sexes, so 'standard' pain medicine is calibrated to the wrong baseline.
Research Gaps
Endometriosis takes 7–10 YEARS to diagnose.
Endometriosis takes an average of 7 to 10 years to diagnose from first symptom — longer than almost any other common condition.
Why: Years of being told it's 'just a bad period' lead to permanent organ damage that could have been prevented.
Research Gaps
75% of women with PCOS are walking around UNDIAGNOSED.
Up to 75% of PCOS cases may be undiagnosed worldwide.
Why: Most women with PCOS never get a name for what's happening, so they can't access treatment.
Research Gaps
Perimenopause research barely exists.
Perimenopause research barely exists compared to menopause research, despite symptoms often starting a decade earlier.
Why: Women are gaslit for years because the science their doctors trained on doesn't really cover this stage.
Diagnosis Delays
HS: 7–10 YEARS to diagnose. Yes, also.
Hidradenitis Suppurativa (HS) takes an average of 7 to 10 years from first symptom to correct diagnosis.
Why: By then, irreversible scarring and tunneling have already set in.
Diagnosis Delays
Heart attacks in women get sent home from the ER.
Women experiencing heart attacks are more likely than men to be sent home from emergency departments without a diagnosis.
Why: Heart attack symptoms in women don't always match the male 'textbook,' and women die because of it.
Diagnosis Delays
Women in pain get sedatives. Men get painkillers.
Women in pain are more likely than men to be prescribed sedatives, while men in the same scenario are more likely to be prescribed pain medication.
Why: The system treats women's pain as anxiety to be calmed, not pain to be treated.
Diagnosis Delays
Women wait 65% LONGER than men for pain meds in the ER.
Women wait on average 65% longer than men to receive pain treatment in emergency departments.
Why: Every extra minute waiting is a measurable consequence of pain bias.
Diagnosis Delays
Autoimmune disease hits women 4x more — and takes 4–5 years to diagnose.
Autoimmune diseases — which affect women 4x more than men — take on average 4 to 5 years and multiple doctors to diagnose.
Why: Women are repeatedly told 'it's stress' before anyone runs the right blood work.
Racial Disparities
Black women are 3x more likely to die in childbirth in the US.
Black women are 2 to 3 times more likely to die from pregnancy-related complications than white women in the United States.
Why: Race is the single strongest predictor of maternal mortality in the US, not income or education.
Racial Disparities
HS hits Black women harder and gets dismissed faster.
Black women have a higher prevalence of HS (0.76%) compared to white women (0.28%) using US population data.
Why: HS is more common, more severe, and more often dismissed in Black women.
Racial Disparities
Doctors still believe myths about Black women feeling less pain.
Black women are significantly more likely than white women to be misdiagnosed or undertreated for pain.
Why: Centuries-old myths about Black bodies feeling less pain still measurably affect clinical decisions today.
Racial Disparities
Racism literally ages Black women's cells faster.
The 'weathering hypothesis' documents that Black women's bodies show signs of accelerated cellular aging due to chronic stress from systemic racism — a peer-reviewed biological finding.
Why: Racism shortens lifespan at the cellular level. This is biology, not metaphor.
Racial Disparities
Indigenous women die in childbirth at 2–3x the white rate.
Indigenous women in the US die from pregnancy-related causes at 2–3x the rate of white women.
Why: The maternal mortality crisis is not only a Black crisis — it spans Indigenous communities too.
Racial Disparities
PCOS doesn't look the same across populations — most tools miss it.
Hispanic and Latina women show higher PCOS prevalence and earlier metabolic complications than non-Hispanic white women.
Why: PCOS doesn't look identical across populations — and most clinical tools were built on white cohorts.
Racial Disparities
South Asian women get diabetes at a 'normal' BMI.
South Asian women develop type 2 diabetes and cardiovascular disease at lower BMI and younger ages than white women — risk that standard calculators miss.
Why: Standard 'normal' BMI ranges underestimate risk in South Asian bodies.
Medical History
Modern medicine was built without women in the room.
For decades, the first clinical trials on humans were conducted without women as standard subjects.
Why: Modern 'evidence-based medicine' was built on a foundation that excluded half the population.
Medical History
Aspirin and beta blockers were approved mostly on male data.
Medications including aspirin and beta blockers were approved based largely on male trial data.
Why: Common drugs you take today were never adequately tested in women before approval.
Medical History
CPR mannequins were male — so women get less effective CPR.
The standard medical mannequin used in CPR training depicted a male body until recently — meaning CPR techniques were not optimized for female anatomy.
Why: Women are less likely to receive bystander CPR, in part because rescuers are trained on the wrong torso.
Medical History
'Hysteria' was an official diagnosis until the 1980s.
'Hysteria' was a formal medical diagnosis applied almost exclusively to women until well into the 20th century.
Why: The reflex to call women's symptoms 'emotional' didn't disappear — it just got rebranded.
Medical History
Gynecology was built on enslaved Black women — without anesthesia.
Modern gynecological surgery was developed by J. Marion Sims through experiments on enslaved Black women without anesthesia.
Why: The field's founding violence still echoes in how Black women's pain is treated today.
Work & Pain
80% of women work through clinically real period pain.
Roughly 80% of women work through menstrual pain despite it meeting clinical definitions of pain that warrants rest.
Why: We pretend period pain is free; the productivity cost is enormous and almost entirely hidden.
Work & Pain
Women lose ~9 productive workdays a year to period pain.
Women with dysmenorrhea lose an average of around 9 productive work days per year — most never report it.
Why: What workplaces call 'lower productivity' is often untreated medical pain.
Work & Pain
Black women take the least time off — and feel the most pain.
Black women are significantly less likely to take medical leave during menstrual pain episodes due to documented cultural and workplace pressures.
Why: Stigma stacks on top of bias, so the women in the most pain take the least time off.
Work & Pain
Endometriosis costs ~11 productive hours per week per employee.
Endometriosis is associated with measurable productivity loss equivalent to about 11 hours per week per affected employee.
Why: If a male-coded condition cost employers this much, there would already be a national policy on it.
Medication & Testing
Women are 50–75% more likely to have bad drug reactions.
Women are 50–75% more likely than men to experience adverse drug reactions.
Why: Dosing 'standards' were calibrated on male bodies; women are essentially overdosed by default for many drugs.
Medication & Testing
Ambien was overdosed in women for YEARS. The FDA only halved it in 2013.
Ambien (zolpidem) was prescribed at the same dose to women and men for years, despite women metabolising it more slowly — the FDA only halved the recommended female dose in 2013.
Why: Decades of women being told they were 'just bad drivers' the next morning were dosing errors.
Medication & Testing
Heart risk calculators were built on white men. They miss YOU.
Standard heart disease risk calculators were developed primarily on white male cohorts and routinely underestimate risk in women, especially BIPOC women.
Why: The screening tool itself is biased, before any doctor opens their mouth.
Medication & Testing
Most FDA drug labels STILL lack sex-specific data.
Sex-specific data is still missing from a large share of FDA-approved drug labels.
Why: If the label doesn't tell your doctor how the drug behaves in a female body, they're guessing.
Current Reality
Endometriosis is a $100 BILLION/year hit we choose to ignore.
The global economic cost of endometriosis in lost productivity and healthcare is estimated at over $100 billion annually.
Why: This is not a niche condition — it is a global economic event we choose to ignore.
Current Reality
PCOS = up to 5x higher endometrial cancer risk.
Women with PCOS are up to 5 times more likely to develop endometrial cancer.
Why: PCOS isn't a cosmetic issue. It's a long-term cancer risk that needs active monitoring.
Current Reality
Perimenopause can start in your mid-30s.
Perimenopause can begin as early as the mid-30s — yet most women are never told this is possible.
Why: When 'this can't be menopause, you're too young' is the standard response, women lose 10+ years of care.
Current Reality
Less than 7% of OB-GYN residencies teach menopause properly.
Less than 7% of OB-GYN residency programs offer comprehensive menopause training.
Why: The specialty most women turn to in perimenopause is largely not trained for it.
Current Reality
1 in 9 US women will get breast cancer — yet screening rules are STILL being argued over.
Around 1 in 9 women in the US will develop breast cancer in her lifetime — yet routine screening guidelines are still being argued over.
Why: Even with this prevalence, women are caught in the middle of guideline debates instead of being protected.
