Yes, and the amount is measured. Lean mass makes up between 25% and 39% of the weight lost on these drugs [2]. Semaglutide sat at 35.2%, liraglutide at 26.8%, tirzepatide at 25.4%.
The comparison that matters is not against nothing. Lifestyle intervention alone came to 26.2%, which is statistically indistinguishable from the drugs at p=0.42 [2]. Losing weight costs lean mass whatever takes it off. That is the comparison most coverage skips.
One thing changed the picture. Adding resistance training brought the share to 17.5% [2]. It was the only intervention in that analysis that did.
Every price on this site buys one thing: the medication, and sometimes a consultation around it. A 2024 review in Diabetes Care argues the medication alone is an incomplete purchase. The argument is specific enough to cost out [1]. Set against what this market charges, it is the clearest example of something a buyer needs that no seller sells.
What comes off besides fat
The review covers semaglutide, liraglutide, tirzepatide and retatrutide. In adults with overweight and obesity they produce roughly 15 to 24 per cent weight loss. Blood pressure, cholesterol, glucose and insulin improve alongside it. It then describes the other half. Lean mass fell by 10% or so, roughly 6 kg. The authors compare that to a decade or more of aging.
What the review says to do about it
Supervised resistance training over more than ten weeks can add large amounts of lean mass, around 3 kg. Strength rose by 25% or so, in both men and women. The authors propose tailored resistance training as an adjunct to incretin therapy specifically to preserve lean mass while achieving fat loss. They also note that after a low-calorie diet, combining aerobic exercise with liraglutide improved weight-loss maintenance compared with either alone.
There is a money argument inside that clinical one. Holding lean mass during treatment could blunt the regain that follows stopping. And one in three reach a year, so stopping is the outcome most buyers meet.
Nobody prices it
Not one seller tracked here includes supervised resistance training in a published figure. A few include coaching, which is not the same thing, and a few include labs. The rest sell the drug and the prescription around it. That is not a criticism of their pricing. It is a description of what the price covers. The gap belongs in a budget, not in a complaint.
Two practical consequences. When comparing two sellers, an inclusion list covering coaching is worth more than the same figure without one. No page quantifies the difference. And against the alternatives, the honest comparison is drug-plus-training, not drug alone. The cost-effectiveness models do not separate those either. The ranked board shows which sellers publish an inclusion list at all.
Price figures are computed from this site’s own records at build time, most recently read September 2026, across 430 priced sellers. The clinical figures are cited.
A share is not an amount
The percentages above are proportions. A drug that takes off more total weight can post a higher share and a similar number of kilograms. A separate meta-analysis of body composition reports the absolute side of that [3], and the two readings answer different questions. Read the share to compare drugs. Read the kilograms to price a gym.