Ozempic, Wegovy, and Muscle Loss After Menopause: What the Research Actually Shows

Quick answer: Semaglutide and tirzepatide trials measure something that rarely comes up before a woman starts the medication. Alongside the fat loss, a meaningful share of the weight that comes off is lean tissue, and lean tissue includes muscle. Trial substudies put that share at roughly 25 to 40 percent of total weight lost. Most of the advice built to protect against this, protein targets and resistance training, addresses only half of what muscle needs to rebuild. Below is what the trial data measures, why the standard protein plan runs into a real wall on these drugs, and what an 8-week human trial found when researchers looked directly inside muscle tissue after shilajit supplementation.

The result is real, and so is what comes off with it

A GLP-1 medication does what it is designed to do. Appetite drops, and the weight comes off, often faster and further than years of previous attempts managed. That result is not in question here.

What gets far less attention in the conversation around these drugs is what else leaves the body along with the fat. Body composition substudies built into the major GLP-1 trials measure this directly with DXA scanning, which separates fat mass from lean mass rather than just tracking pounds on a scale. Across several of these substudies, a real share of total weight lost is lean tissue rather than fat, and muscle makes up most of that lean-tissue category.

What the trial data actually measured

In the STEP 1 trial's DXA substudy, people taking semaglutide lost 9.7 percent of their total lean body mass over the course of the study. In the SURMOUNT-1 DXA substudy of tirzepatide, roughly 26 percent of total weight lost, about 5.6 kilograms, was lean tissue. A 2025 review pulling together data across multiple GLP-1 trials put the range at roughly 25 to 40 percent of total weight lost coming from lean tissue.

These are trial measurements, not a claim that applies identically to every person on these medications. Diet quality, activity level, dose, and duration all move the number. But the direction is consistent across every substudy that has looked, and it applies to women in their 50s and 60s exactly as it applies to trial participants overall.

Why the standard protein plan runs into a real wall

The advice given to protect muscle on a GLP-1 medication is almost always the same. Eat more protein, generally somewhere around 1.6 grams per kilogram of body weight per day, and lift weights several times a week.

That advice is not wrong. Protein supplies the raw material muscle needs to rebuild, and resistance training gives the body a reason to use it. The problem is a practical one that shows up constantly in the accounts of women taking these medications. The same appetite suppression that makes the drug effective for weight loss also makes hitting a high daily protein target genuinely difficult. A 6-ounce chicken breast can feel like more food than an appetite that has been chemically dialed down can manage, and pushing through that discomfort meal after meal is not sustainable for most people.

There is a second, less visible problem underneath the first one. Even among people who do manage to hit their protein targets and keep up a consistent lifting schedule, muscle loss on these medications still shows up. Protein is the material. The signal that tells the body to put that material to use rebuilding muscle tissue is a separate biological system, and it is the part that a protein target and a set of squats do not address.

What an 8-week trial found when researchers looked inside muscle tissue

Here is exactly what that research measured, and where it stops short.

In an 8-week human trial, 16 healthy adults took 500 milligrams of shilajit daily, and researchers took biopsies of muscle tissue to measure gene activity directly, rather than relying on a strength test or a scale. The results, read through RT-PCR analysis, showed a cluster of 17 genes tied to muscle repair and the extracellular matrix, the collagen scaffold that holds muscle fibers together, switched on. The collagen genes in that cluster rose substantially over baseline, with the 3 largest increases at roughly 5.2, 5.1, and 4.6 times higher than before supplementation (https://pubmed.ncbi.nlm.nih.gov/27414521/). This is a gene-expression finding in a small mixed group, not a study that measured muscle mass gained on a tape measure, and it should be read as exactly that. What it shows is that shilajit switched on the muscle's own rebuilding machinery at the cellular level, distinct from simply supplying more raw material for that machinery to use.

A separate 8-week randomized controlled trial in 63 active men tested shilajit against a placebo under a fatigue protocol. The men taking 500 milligrams daily retained significantly more of their maximal strength after repeated fatigue than the placebo group did, and a marker of connective tissue breakdown, hydroxyproline, was lower in the shilajit group (https://pubmed.ncbi.nlm.nih.gov/30728074/). This trial was conducted in men, and that limitation should be stated plainly rather than glossed over. It does not establish that the same effect occurs at the same magnitude in postmenopausal women. What it adds to the muscle-biopsy finding is a second, independent measurement pointing at the same rebuilding signal, this time showing up as strength retained rather than strength lost.

Read together, these are 2 real, controlled human trials, not marketing claims, and neither one says shilajit builds muscle mass by itself. What they show is a rebuilding signal switched on at the cellular level and strength held onto under stress, which is a different mechanism than the raw-material approach that protein and creatine take.

For the woman worried about estrogen and cancer risk

Any conversation involving cellular signaling in the body eventually runs into a reasonable question about hormones, especially for a woman with breast cancer in her family history. Shilajit is not a hormone and does not add estrogen to the body. Laboratory research has tested shilajit directly against MCF-7 and MDA-MB-231 cells, the most studied estrogen-receptor-positive breast cancer cell lines used in research, and found that it reduced the viability of those cancer cells and triggered programmed cell death, while normal breast cells in the same experiments were left unharmed (https://pubmed.ncbi.nlm.nih.gov/34466597/). That is laboratory, cell-line research, not a human cancer trial, and it should be read as exactly that. It is also the reason this compound does not carry the same hesitation a synthetic hormone conversation usually does.

Safety and the purity question

Across every human clinical study conducted on shilajit, zero serious adverse events have been reported. It is not a stimulant, and it does not act on appetite or blood sugar, which is why it works on a separate system from a GLP-1 medication rather than interfering with it.

Purity is a fair thing to ask about any mineral resin. Optimum shilajit comes from the Altai mountains, cold pressed and purified, and every batch is third-party lab tested for both heavy metals and mycotoxins, with results posted. Optimum is a small, family owned company out of Florida, and a real person answers when a customer reaches out. It ships as a box of tablets, not a loose raw powder that loses potency before it reaches the person taking it.

What this actually means for you

If a GLP-1 medication is working for you, nothing in this research is a reason to reconsider it. The weight loss is real and it matters. What the research points to is a gap in the plan built around the medication, a plan that hands most women a protein target and a workout schedule and calls the muscle question answered, while the appetite suppression that makes the drug work also makes that protein target genuinely hard to hit, and while the rebuilding signal underneath it all rarely gets mentioned at all.

Keeping the medication and adding attention to that signal are not opposite choices. They are the same plan, with the missing layer added back in.

If you want to give your muscle the signal the research points to, you can find Optimum Shilajit here: https://www.liveoptimum.co/products/optimum-shilajit

References

1. Das A, et al. The human skeletal muscle transcriptome in response to oral shilajit supplementation. Journal of Medicinal Food. 2016. https://pubmed.ncbi.nlm.nih.gov/27414521/
2. Keller J, et al. Effect of shilajit on maximal strength retention under fatigue, randomized controlled trial in active men. Journal of the International Society of Sports Nutrition. 2019. https://pubmed.ncbi.nlm.nih.gov/30728074/
3. Wilding JPH, et al. STEP 1 trial DXA substudy, body composition changes with semaglutide. Journal of the Endocrine Society. 2021. https://pmc.ncbi.nlm.nih.gov/articles/PMC8089287/
4. Look M, et al. SURMOUNT-1 DXA substudy, body composition changes with tirzepatide. Diabetes, Obesity and Metabolism. 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC11965027/
5. Rossi A, et al. Lean mass loss across GLP-1 receptor agonist trials, review. Acta Diabetologica. 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12957034/
6. Rahmani Barouji S, et al. Shilajit inhibited breast cancer cell proliferation and induced apoptosis while sparing normal breast cells. 2020. https://pubmed.ncbi.nlm.nih.gov/34466597/