Women in midlife who were using menopause hormone therapy lost somewhat more weight on Ozempic-style drugs than women who were not, according to a study from researchers at Mayo Clinic Florida1. The work was presented at The Menopause Society’s annual meeting2. It is a look back at health records, so it shows that the two things went together, not that hormone therapy caused the extra weight loss.
The drugs in question belong to the GLP-1 family, medicines that copy a gut hormone that helps control appetite. The study covered semaglutide, sold as Ozempic and Wegovy, and tirzepatide, sold as Mounjaro and Zepbound1.
What the researchers did
The team searched electronic health records for women aged 45 and older with overweight or obesity who had been prescribed one of the two drugs1. Healio reported the cutoff as a body mass index (a weight-for-height score) of at least 272. They then compared women who were also using menopause hormone therapy with women who were not1.
The two reports describe the size of the study a little differently. Newsweek said the semaglutide group included 2,379 women and the tirzepatide group 1,476 women1. Healio described the study as including 2,379 women using either drug2.
To make the comparison fairer, the researchers used a method called propensity score matching. It pairs up women who are alike in measured ways, here age, body mass index, earlier use of obesity medicines and whether they had type 2 diabetes1.
The results so far
Among women taking semaglutide, those on hormone therapy lost noticeably more weight starting at nine months1. Healio reported these averages for women on hormone therapy compared with non-users2:
- At 9 months: 9.8% of body weight lost versus 8.2%2
- At 1 year: 11% versus 9.5%2
- At 15 months: 11.6% versus 9.7%2
- At the last follow-up: 11.9% versus 10.9%2
Women on hormone therapy were also a little more likely to reach bigger weight-loss goals. In the semaglutide group, 55% lost at least 10% of their body weight compared with 51% of non-users, and 13% lost at least 25% compared with 10%1. Healio added that 22% versus 18% lost at least 20%, and 6% versus 4% lost at least 30%2.
For a person weighing 200 pounds, the gap at 15 months works out to roughly four pounds on average. That is a real difference in the data but a modest one.
The picture with tirzepatide was weaker. Women on hormone therapy lost slightly more weight in the first three months, but the differences at later time points were not statistically significant, meaning they could plausibly be due to chance1. Healio quoted the researchers as describing “a similar directional effect” that “did not reach statistical significance”2.
“The observed association appeared stronger among women using semaglutide than among those using tirzepatide, although our study was not designed to directly compare the two medications, and the tirzepatide sample was smaller,” lead author Dr. Regina Castaneda told Newsweek.1
Castaneda said one possible reason is that tirzepatide produces more weight loss overall, which may leave less room to spot any extra effect from hormone therapy1.
What it does not show yet
Because the study only looked back at records, it cannot say whether hormone therapy is the reason for the difference. Castaneda told Healio that “because our study was observational, we cannot establish causality or determine the mechanisms underlying the association we observed”2. She called the results hypothesis-generating, meaning they point to a question for future trials rather than answer it2.
She named a “healthy-user effect” as one possibility: women who use hormone therapy may differ from non-users in ways that also affect weight2. Dr. Jessica Duncan, chief medical officer at Ivím Health and an obesity medicine physician who was not involved, made the same point to Newsweek.
“Women on hormone therapy are often healthier, more engaged with their care and better supported, and the matching may not have captured all of that,” Duncan said.1
Duncan said a randomized clinical trial, in which women are assigned by chance to hormone therapy or not, would be needed to learn whether hormone therapy directly improves weight loss on these drugs1. The sources describe a meeting presentation and interviews; they do not point to a full peer-reviewed paper.
The researchers also stressed what the findings should not be used for. “Weight loss is not an indication for menopause hormone therapy,” Castaneda said1. She said that for women who already have bothersome menopause symptoms and are suitable candidates for hormone therapy, the findings offer reassurance that it may bring added metabolic benefits alongside GLP-1 drugs1.
Possible explanations being studied
Castaneda pointed to lab and animal research. “Preclinical studies have shown that estrogen can amplify the appetite-suppressing effects of GLP-1 signaling,” she told Newsweek1. Preclinical means work done in cells or animals before testing in people. She told Healio that estrogen may also influence food-reward pathways in the brain2. She added that estrogen affects energy balance, insulin sensitivity and body composition1.
A second idea is less about biology and more about daily life. Castaneda told Healio that relieving hot flashes, poor sleep and low quality of life with hormone therapy may make it easier for women to keep up healthy eating and exercise habits2.
Who is behind it
The lead author, Regina Castaneda, is a postdoctoral research fellow at the Mayo Clinic College of Medicine and Science2. The available reports do not describe who funded the study. Semaglutide is made by Novo Nordisk and tirzepatide by Eli Lilly2; the sources do not say whether either company was involved.
The outside expert quoted by Newsweek, Duncan, is chief medical officer of Ivím Health1. She said the results are consistent with what she sees in her own practice1.
How it fits the field
Castaneda told Healio that weight gain is one of the most common concerns among midlife women. As estrogen falls, the body tends to store more fat around the organs, burn less energy at rest and lose muscle2. She said many women are hearing claims in the news and on social media that hormone therapy boosts weight-loss drugs, and that until now the idea rested mainly on observational studies2.
Those claims have been around for some time. A 2024 article from Midi Health, a company that provides menopause care, said combining hormone therapy with semaglutide “may improve weight reduction”3. The same article cited an average weight gain of 1.5 pounds per year in midlife3. The new study adds a larger set of records to that conversation, but it is still the same kind of evidence.
Biohack has also covered other recent research on both treatments, including findings on modern hormone therapy and heart attacks or strokes and on Ozempic-style drugs in people with prediabetes.
What to watch next
- Whether the full study is published in a peer-reviewed journal, with more detail on how the groups were matched.
- Whether a randomized trial is set up to test hormone therapy alongside GLP-1 drugs, as both Castaneda and Duncan said is needed12.
- Whether larger tirzepatide groups show a clearer pattern, given the smaller sample in this study1.
