A sweeping new study has uncovered a troubling two-way relationship between long COVID and menstrual health that could affect millions of women worldwide. The research reveals that women with persistent COVID symptoms face significantly higher risks of abnormal uterine bleeding, while their long COVID symptoms intensify dramatically during certain phases of their menstrual cycles.
The findings, published in Nature Communications, emerge from one of the most comprehensive investigations to date examining how long-term COVID symptoms interact with reproductive health. French and British researchers analyzed data from over 12,000 women, tracked symptoms in real-time across menstrual cycles, and examined blood and tissue samples to uncover the biological mechanisms at work.
The Hidden Burden on Women’s Health
Among the 1,048 women with long COVID in the study, reports of heavy menstrual bleeding increased by a staggering 93% compared to those who never contracted the virus. These women also experienced periods lasting longer than eight days at more than double the rate of uninfected women, alongside increased bleeding between periods.
“Long COVID was associated with AUB in a UK population. When compared to those never infected, long COVID participants reported increased menstrual volume, duration and intermenstrual bleeding.”
The research team, led by scientists from the University of Edinburgh and France’s National Centre for Scientific Research, found that women who had recovered from acute COVID showed minimal menstrual disruption. This suggests something unique about persistent COVID symptoms drives these reproductive health changes.
What makes these findings particularly concerning is the scale of potential impact. Long COVID affects an estimated 3-7% of the global population, with women twice as likely as men to develop the condition. For reproductive-age women already dealing with debilitating fatigue and other long COVID symptoms, menstrual disruption adds another layer of health challenges.
When Symptoms Surge
The study’s most intriguing discovery came from tracking 54 women with long COVID through multiple menstrual cycles using a smartphone app. Researchers found that symptom severity peaked during two specific phases: the days immediately before and during menstruation, and the proliferative phase that follows.
During these periods, women experienced significantly worse fatigue, headaches, dizziness, muscle aches, and post-exertional malaise. The timing suggests that hormonal fluctuations, particularly the sharp drop in progesterone before menstruation, may trigger inflammatory responses that worsen long COVID symptoms.
“Long COVID symptom severity was highest during the perimenstrual and proliferative phases.”
This cyclical pattern could help explain why long COVID affects women disproportionately and why symptoms can seem unpredictable. For healthcare providers, it suggests that timing treatments around menstrual cycles might improve outcomes for female patients.
The research team analyzed blood samples and found elevated levels of inflammatory markers during menstruation in women with long COVID, supporting the theory that immune system dysfunction underlies both conditions. They also discovered unusual clusters of immune cells in the uterine lining of affected women, though the exact role of these cell aggregates remains unclear.
Surprisingly, standard reproductive hormones like estrogen and progesterone appeared largely normal in women with long COVID. However, levels of dihydrotestosterone, a potent form of testosterone, were significantly higher during certain cycle phases. This finding points to disrupted androgen metabolism as a potential contributor to menstrual irregularities.
The study’s authors emphasize that their findings should prompt new therapeutic approaches specifically designed for women with long COVID. They suggest that anti-inflammatory treatments timed to the menstrual cycle, or hormonal interventions to prevent progesterone withdrawal, might help manage both long COVID symptoms and menstrual disruption.
For the estimated 400 million people worldwide who have experienced long COVID, with women representing a disproportionate share, these insights could not come soon enough. The research provides the first concrete evidence that menstrual health considerations should be integral to long COVID treatment strategies.
The implications extend beyond individual patient care. Heavy menstrual bleeding already affects one in three women globally and represents a major cause of anemia and lost productivity. If long COVID increases these rates significantly, healthcare systems may need to prepare for additional demands on gynecological services.
While the study focused primarily on white, educated women in the UK, the researchers call for broader investigations across diverse populations to confirm their findings. They also acknowledge that some women with the most severe menstrual disruptions may have been excluded from their hormone studies, potentially underestimating the full scope of the problem.
As long COVID research continues to evolve, this study marks a crucial step toward understanding how the condition affects women differently than men. For healthcare providers treating long COVID patients, the message is clear: asking about menstrual health isn’t just good practice, it’s essential for comprehensive care.
Nature Communications: 10.1038/s41467-025-62965-7
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