Popular weight-loss drugs like semaglutide (Ozempic/Wegovy) may be affecting menstrual cycles. A new pharmacovigilance study found that GLP-1 receptor agonists — especially semaglutide — are disproportionately associated with heavy bleeding, intermenstrual bleeding, and menstrual clots in women of reproductive age. Tirzepatide showed similar but weaker signals, while liraglutide showed none.
Popular weight-loss drugs may come with an unexpected side effect for women: disrupted periods. A new study published in Obstetrics & Gynecology analyzed over 14 million reports from the FDA Adverse Event Reporting System (FAERS) and found that GLP-1 receptor agonists — particularly semaglutide — are disproportionately linked to heavy menstrual bleeding, intermenstrual bleeding, and menstrual clots in reproductive-aged women (ages 12–55).
Semaglutide showed the strongest signals, with a notably higher reporting odds ratio for menstrual clots compared to other drugs. Tirzepatide also flagged for intermenstrual bleeding and clots, though with weaker signals. Liraglutide showed no significant menstrual associations. Researchers suggest the effects may stem from GLP-1 receptors in endometrial tissue, weight-loss-driven changes in estrogen metabolism, and altered coagulation pathways.
Key Takeaways:
Why it matters: With millions of women taking GLP-1 drugs for weight loss or diabetes, these findings raise important questions about underrecognized gynecological side effects. Clinicians should be aware of potential menstrual disruptions when prescribing these medications to reproductive-aged patients.
