Good news for women of a certain age: Hormone replacement therapy for menopause appears to boost the effectiveness of GLP-1 weight loss drugs like Wegovy and Zepbound, a new study says.

Women using tirzepatide (Zepbound) lost more weight if they also were taking hormone therapy — 17% of body weight lost versus 14% after a median 18 months, researchers reported Saturday at the Endocrine Society’s annual meeting in San Francisco.

Further, more women taking Zepbound and hormone therapy achieved at least 20% total body weight loss, with 45% meeting this goal compared to 18% of those not on hormone therapy.

“These data are the first to show the combined use of tirzepatide and menopause hormone therapy significantly increases treatment effectiveness in postmenopausal women,” presenting investigator Dr. Regina Castaneda, a research fellow in endocrinology at the Mayo Clinic in Jacksonville, Fla, said in a news release.

Casteneda noted that previous studies of semaglutide (Ozempic/Wegovy) yielded similar findings.

“Achieving these outcomes with a second obesity medication may indicate a broader efficacy trend for pairing these two classes of medications,” Castenada said.

More women are using hormone therapy to manage menopause symptoms like hot flashes and night sweats, following research that found such therapy didn’t increase risk of diseases like breast cancer and heart disease as dramatically as previously thought.

Menopause-related hormone changes often result in increased belly fat and decreased muscle mass, as well as changes in metabolism that contribute to weight gain, researchers said in background notes.

For the new study, researchers tracked the weight of 120 postmenopausal women prescribed Zepbound. Of those women, 40 were also using hormone therapy and 80 weren’t.

Glucagon-like peptide-1 (GLP-1) drugs mimic the GLP-1 hormone, which helps control insulin and blood sugar levels, decreases appetite and slows digestion of food.

“The information garnered through this new study provides important insights to develop more effective and personalized weight management interventions to reduce a postmenopausal woman’s risk of overweight and obesity-related health complications,” senior researcher Dr. Maria Daniela Hurtado Andrade, an assistant professor of medicine at the Mayo Clinic, said in a news release.

“This study underscores the urgent need for further research to better understand how obesity medications and menopause hormone therapy work together,” Andrade added. 

“Gaining this knowledge could greatly improve the health and well-being of millions of postmenopausal women," she added. "It also points to the need for better strategies to make these treatments more accessible and available to those who need them.”

However, researchers noted that larger studies involving more women are needed to confirm their findings and figure out why hormone therapy might boost GLP-1 drug effectiveness.

Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.