We don't know yet whether the muscle loss is caused by the drug itself or due to the weight loss, there are some studies but I haven't seen any conclusion yet one way or the other.
Anecdotally, a friend of mine was on a diet and exercise regime, then at some point he switched to Mounjaro to reduce cravings, while keeping the same diet and exercise regime (he's a data geek so he documented things pretty well), and his muscle gain maybe slowed a tiny bit, but didn't reverse on Mounjaro.
Anecdotally, a friend of mine was on a diet and exercise regime, then at some point he switched to Mounjaro to reduce cravings, while keeping the same diet and exercise regime (he's a data geek so he documented things pretty well), and his muscle gain maybe slowed a tiny bit, but didn't reverse on Mounjaro.
Sample size of one, but at least it's not zero.