Scientists at Mayo Clinic and Wayne State University discovered that post-menopausal women taking tirzepatide for weight loss achieved 35 percent greater bodyweight reduction when also using hormone therapy.
The retrospective study analyzed health data from 120 women in their 50s over 18 months. Participants taking both tirzepatide and hormone therapy lost an average of 19.2 percent of starting body weight compared to 14 percent for those on tirzepatide alone.
The research builds on a 2024 Mayo Clinic study showing similar results with semaglutide and hormone therapy combination. Lead researcher Regina Castaneda noted the magnitude of difference warrants further investigation.
Tirzepatide, sold as Zepbound or Mounjaro, belongs to the GLP-1 drug class that has revolutionized weight loss treatment. The study did not differentiate between types or doses of hormone therapy administered.
Researchers theorize estrogen may enhance the body's natural GLP-1 signaling system based on rodent studies. However, alternative explanations include healthier behavioral patterns among women already engaged in hormone therapy.
The Mayo team plans randomized controlled trials to confirm the synergistic effects and determine whether hormone therapy enhances cardiovascular metabolic benefits beyond weight loss.