Mounjaro and menopause: in postmenopausal women in the SURMOUNT-1 trial, tirzepatide (Mounjaro) led to a 23% weight loss against 3% on placebo, close to the result in premenopausal women (26% against 2%), according to a post hoc analysis published in Obesity in 2025. Menopause does not cancel the measured effect of the drug, but data on muscle, bone and hormone therapy are much thinner.
Mounjaro and menopause: what do the studies show in postmenopausal women?
You may have heard that menopause makes weight-loss drugs work less well. For Mounjaro, the most precise analysis available says otherwise: at the end of treatment, the average weight loss in postmenopausal women in SURMOUNT-1 (23%) was close to that of premenopausal women (26%) and far above placebo (3%). It builds on the clinical trial results for Mounjaro, with SURMOUNT-1 as the pivotal study.
The analysis, by Tchang and colleagues in Obesity, takes women from three SURMOUNT trials (1, 3 and 4). They were classified after the fact as premenopausal, perimenopausal or postmenopausal, then compared depending on whether they received tirzepatide (15 mg or maximum tolerated dose) or placebo. Here are the SURMOUNT-1 results, in women with obesity or overweight and without type 2 diabetes.
| Reproductive stage | Weight: tirzepatide | Weight: placebo | Waist: tirzepatide | Waist: placebo |
|---|---|---|---|---|
| Premenopause | −26% | −2% | −22 cm | −4 cm |
| Perimenopause | −23% | −3% | −20 cm | −5 cm |
| Postmenopause | −23% | −3% | −20 cm | −4 cm |
Another benchmark from the same analysis: across all three stages, 97% to 98% of women on tirzepatide lost at least 5% of their weight, against 29% to 33% on placebo. Among those with a starting BMI below 35, 30% to 52% reached a waist-to-height ratio of 0.49 or lower, the cut-off the authors used for low central adiposity.
These numbers call for a careful reading. This is a post hoc analysis, so it was not planned in the original protocol, and its authors include employees of Eli Lilly, the maker of Mounjaro. The doses (15 mg or maximum tolerated) are not those of every patient, which partly explains why the figures exceed the averages in SURMOUNT-1 in the New England Journal of Medicine (−15.0%, −19.5% and −20.9% at 5, 10 and 15 mg, mixed population). The two sets of figures cannot be compared directly. In the US, the same molecule for weight management is sold as Zepbound.
For semaglutide (Wegovy, Ozempic), the Spanish Menopause Society says it has the most menopause-specific evidence of the incretin drugs, but that this evidence is still limited and mostly observational. We could not verify a reliable figure for postmenopausal women, so we quote none.
Why do weight and body composition change at menopause?
At menopause, it is less the number on the scale that moves than what the scale is made of: fat mass rises faster and lean mass, including muscle, falls. In the American SWAN cohort, followed with DXA body scans, the rate of fat gain doubled at the start of the menopause transition while lean mass declined, and this continued until two years after the final period.
The authors, Greendale and colleagues in JCI Insight (2019), add a useful detail: total weight did not speed up at the transition, then flattened afterwards. In other words, the scale can look stuck while your shape and waistline change. After that two-year window, the fat and lean mass curves levelled off in this cohort.
What this means if you take Mounjaro:
- Weight alone does not tell the whole story. A shrinking waist with a scale that barely moves is still an encouraging sign. It is one of the measures in the SURMOUNT-1 analysis above.
- Muscle becomes a priority. If menopause already pulls lean mass down, fast weight loss deserves extra attention to that component.
- Timing matters. The transition is when changes are fastest; patience and regular tracking beat judging a single weigh-in.
Does Mounjaro cause muscle and bone loss at menopause?
Mounjaro mainly removes fat, but it also removes muscle: in the SURMOUNT-1 DXA substudy, about 75% of the weight lost was fat mass and 25% was lean mass, a proportion close to placebo. No substudy measured these proportions specifically in postmenopausal women, and the effect on bone remains poorly documented.
The detail comes from Look and colleagues in Diabetes, Obesity and Metabolism (2025): 160 SURMOUNT-1 participants (73% women) had a DXA scan at baseline and at 72 weeks. On tirzepatide, body weight fell 21.3%, fat mass 33.9% and lean mass 10.9% (against 5.3%, 8.2% and 2.6% on placebo). The proportions stayed consistent in most subgroups, including by age band and sex. Keep in mind that the group is small and it is not a menopause study.
For bone, the picture is blurrier. The European product information we consulted does not mention a specific effect of Mounjaro on bone density. A 2026 review of GLP-1 drugs in menopause concludes that larger studies are needed, including on bone density. The Spanish Menopause Society, for its part, puts muscle and fracture risk into the monitoring framework for these drugs.
What these experts recommend, and what you can raise with your doctor:
- Resistance training, rather than walking alone. Our article on preventing muscle loss on GLP-1 drugs explains how.
- Enough protein, calibrated with a professional for your situation.
- A conversation about fracture risk if you have a family history, a small frame or a medicine that weakens bone.
- Attention to skin and shape: for loose skin after weight loss, acting early helps.
Can you take Mounjaro with menopausal hormone therapy?
No study answers this directly: the European product information for Mounjaro does not cover menopausal hormone therapy (MHT). The only hormonal interaction it documents involves a combined oral contraceptive, and it does not allow a conclusion for MHT. The data are missing.
Here is what the European Mounjaro file says. A single 5 mg dose of tirzepatide given with a combined oral contraceptive (ethinylestradiol and norgestimate) lowered the peak blood level of ethinylestradiol by 59% and its total exposure by 20%, with a delay of about 4 hours. The text concludes that this reduction after a single dose is not considered clinically relevant and that no dose adjustment of the contraceptive is required. The proposed mechanism is slower stomach emptying.
A line of reasoning follows, and it is only reasoning: a pill passes through the stomach, a skin patch or gel does not. Oral forms of MHT might therefore be more affected than transdermal ones, but no study has tested it. A 2026 review in Maturitas by Viana and colleagues reaches the same caution: no data exist for the progestogens used in MHT or in gynaecology, the interaction is described as biologically plausible but unproven, and any risk would be concentrated at the start of treatment and during dose increases, since the effect on gastric emptying is greatest after the first dose.
One last point on efficacy: a link between MHT and greater weight loss has been seen with semaglutide, but the Spanish Menopause Society calls it hypothesis-generating and says it should not justify starting MHT to lose more weight. Your prescribers, or your doctor if it is the same person, should know about both treatments. Do not change, stop or split either one on your own.
Do you still need contraception on Mounjaro during perimenopause?
Yes, you should keep using contraception until your doctor has confirmed menopause. The European product information recommends that women of childbearing potential use contraception on tirzepatide, and says to stop treatment at least one month before a planned pregnancy because of its long half-life.
Perimenopause is exactly the stage when periods turn irregular while fertility has not gone away: spaced-out cycles do not mean menopause. If you take a pill, the question for your doctor or pharmacist is which method suits you best, especially when you start and at each dose increase, because that is when the effect on gastric emptying is strongest. We cover this in our article on Mounjaro and oral contraception.
Which symptoms should you watch on Mounjaro during menopause, and when should you see a doctor?
On Mounjaro, some signs warrant a call to your doctor at any age, and menopause adds a few to keep in mind. Prolonged digestive trouble comes first: the European product information warns that it can lead to dehydration, and advises drinking enough fluids.
- Vomiting or diarrhoea that will not stop, with strong thirst, little urine or dizziness: dehydration risk. Hot flushes and night sweats could add to fluid loss; that is our inference, not a finding.
- Severe pain in the belly or under the ribs, especially after a meal: the product information lists gallbladder events (gallstones) with these drugs. Report it without waiting.
- Muscle weakness, unusual breathlessness on effort, bone pain or a fall: worth raising to check on muscle and bone.
- Unusual vaginal bleeding, especially after menopause: do not put it down to the drug before a medical opinion.
- An unexplained late period in perimenopause: consider pregnancy and talk to your doctor before the next injection.
- Worsening sleep, mood or hot flushes: a 2026 review reports a few studies suggesting an effect of GLP-1 drugs on vasomotor symptoms, but they are too limited to count as an indication.
For day-to-day tracking, log your weigh-ins, injections and side effects in the MounjaGO app: its PDF report helps you show your doctor the trend over several weeks. And before the appointment, check your BMI and weight-loss projection or compare Mounjaro prices and coverage.
What are the limits of this data?
Data on Mounjaro in menopause are scarce, recent and mostly drawn from secondary analyses funded by the manufacturer. They describe group averages and do not predict what you personally will see. Several limits, listed below, frame how to read these findings with caution.
- The analysis by reproductive stage is post hoc: women were classified after the trial, and the trials were not designed for menopause.
- The DXA substudy covers only 160 people, 73% of them women, with no menopause-specific analysis.
- We found no published data on bone density, fractures or vasomotor symptoms on Mounjaro in postmenopausal women.
- No data exist on combining Mounjaro with MHT, oral or transdermal, or on the progestogens used to protect the womb lining.
- The semaglutide figures for postmenopausal women could not be verified here.
- Product information changes: check the current version with your pharmacist or your national regulator.
Frequently asked questions
Does Mounjaro work as well after menopause?
In the SURMOUNT-1 post hoc analysis, postmenopausal women lost 23% of their weight on tirzepatide on average, against 26% in premenopause and 23% in perimenopause. The gap with placebo stayed clear at all three stages. These are group averages, not an individual promise.
Can you take Mounjaro with HRT?
No study has evaluated it: the data are missing. The only documented effect involves a combined oral contraceptive, with a drop in absorption that the manufacturer and the EMA do not consider clinically relevant. Do not stop or change your HRT on your own: talk to your doctor or pharmacist.
Does Mounjaro make menopausal muscle loss worse?
No study measures this specifically in postmenopausal women. In the SURMOUNT-1 DXA substudy, about a quarter of the weight lost was lean mass, close to the placebo proportion. Resistance training and enough protein are what experts recommend.
Does Mounjaro relieve hot flushes?
Nothing allows us to say so. A 2026 review mentions a few studies suggesting better vasomotor symptoms with GLP-1 drugs, but they are limited and not specific to Mounjaro. Mounjaro is not a treatment for menopause symptoms.
Sources
- Tchang BG, Mihai AC, Stefanski A et al. “Body weight reduction in women treated with tirzepatide by reproductive stage: a post hoc analysis from the SURMOUNT program”. Obesity, 2025. PMID 40074721, accessed .
- Greendale GA, Sternfeld B, Huang M et al. “Changes in body composition and weight during the menopause transition”. JCI Insight, 2019. PMID 30843880, accessed .
- Look M, Dunn JP, Kushner RF et al. “Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study”. Diabetes, Obesity and Metabolism, 2025. PMID 39996356, accessed .
- Jastreboff AM, Aronne LJ, Ahmad NN et al. “Tirzepatide once weekly for the treatment of obesity” (SURMOUNT-1). New England Journal of Medicine, 2022. PMID 35658024, accessed .
- European Medicines Agency, Mounjaro: EPAR and summary of product characteristics (sections 4.4, 4.5 and 4.6). ema.europa.eu, accessed .
- Viana DPDC, Invitti AL, Jacobsen L, Schor E. “Tirzepatide and oral progestogens: a hypothesis-generating review…”. Maturitas, 2026. PMID 42721915, accessed .
- Sánchez-Prieto M, Romero-Domínguez M, Orozco R et al. “Incretin-based therapies in peri- and postmenopausal women with obesity: an expert position statement from the Spanish Menopause Society”. Maturitas, 2026. PMID 42664617, accessed .
- Graczyk NA, Bisschops J. “GLP-1 receptor agonists for obesity and symptoms in menopause: a review”. Cureus, 2026. PMID 41704988, accessed .
Medical disclaimer. This article is for information only and does not replace medical advice. The figures quoted are clinical trial averages and do not predict your individual result. Nothing here is a recommendation on dose, hormone therapy or contraception: any decision to start, change or stop a treatment should be made with your doctor or pharmacist. Review closed on 5 October 2026.