How to Keep Muscle on a GLP-1: Protein, Strength Training, Pace

You lose some muscle along with fat

When you’re losing weight, you’re not only losing fat. That would be great, but it doesn’t work like that. You do lose some muscle too. In some of the larger studies, a pretty significant portion of the weight loss, in some cases up to around a quarter, was lean mass, which is muscle mass, rather than fat.^[1]

In the SURMOUNT-1 substudy, about 25% of weight lost on tirzepatide was lean mass. A 2026 review of 35 incretin trials found a median of about 28%, with about two thirds of studies above 25%.^[2]

That’s very important because we need to hold on to muscle as much as we can. It drives our metabolism. It helps us recover, prevent injury, keeps us steady on our feet. It’s also one of the best predictors of how well people age.

So the goal is not, strictly speaking, a lower number on the scale. The goal is a lower number while preserving muscle mass. And there’s really three things to focus on there.

1. Protein, at every meal and first

The first is protein. Obviously, these medicines turn down people’s appetite, but it’s not selective. It turns down your appetite for everything.

In a lot of cases, people find that they have less of an appetite for protein. That may be because it’s more filling. It typically takes more effort. It’s a lot easier for someone to take a few small bites of something simple like yogurt versus chewing a pork chop.

But protein is probably the most important thing here.^[3] We advise people, make sure you get it at every meal. Try to get it as the first thing that you eat at your meal so that if you do get full, you’ve at least got your protein in. Protein shakes also can be helpful, but it’s very important to make sure you get enough protein.

2. Some form of strength training

The second is some form of strength training. And that doesn’t have to mean lifting giant heavy weights. It just means lifting something two or three times a week.

It doesn’t have to be anything fancy. It actually doesn’t even really have to be a lift. It can also be bands or body weight lifts, machines. Any form of resistance training is what we need. That’s the signal that tells your body to hold on to muscle, even though you might be losing weight.^[4]

Walking and cardio, obviously great for your overall health. They do not do anything to help with the signal to hold on to muscle.

3. Pace: about one to two pounds a week

Third thing is pace. Typically, about one to two pounds a week is a good target. Obviously, that can change a little depending on where you start and your goals.

But if you’re losing much faster than that, then it can actually be a red flag that you’re also losing some muscle along with fat. And that’s probably the time that we need to have a conversation about how much you’re eating.

Who is most at risk?

People who are at risk of muscle loss: no surprise, people with less muscle to begin with are at more risk of losing it. The elderly, especially women after menopause.^[5] People who are not doing really any resistance training or strength training.

Also, if you’re barely eating and you’re not getting in your protein or really any calories, then it may be that the medicine is too high and we need to talk about going down on it.

So it doesn’t mean that you’re not a candidate for a GLP-1. You still can be. It just means we have to make a few tweaks. That’s all part of the plan that we individualize for each person.

More from Dr. Snipes on women in their 40s and 50s: peptides in perimenopause. See also GLP-1 muscle loss.

How to get tirzepatide or semaglutide

Compounded tirzepatide and semaglutide need a prescription. At Rx Peps Direct, a licensed provider reviews your history for a $39 medical review per order, covering up to three peptides, and sets the dose. If approved, a licensed U.S. 503A pharmacy prepares it and bills the medication at wholesale, in 28 states plus Washington, DC. Tirzepatide is a 30-day supply at most. Browse weight-loss medications or compare semaglutide vs tirzepatide.

This article is educational and is not medical advice. Compounded tirzepatide and semaglutide are not FDA approved.

Sources

1. Look M, et al. Body composition changes during weight reduction with tirzepatide in the SURMOUNT-1 study of adults with obesity or overweight. Diabetes Obes Metab. 2025;27(5):2720-2729. doi.org/10.1111/dom.16275
2. Batsis JA, et al. Effect of incretin-based and nonpharmacologic weight loss on body composition: a systematic review. Ann Intern Med. 2026;179(7):996-1013. doi.org/10.7326/ANNALS-25-00478
3. Kim JE, et al. Effects of dietary protein intake on body composition changes after weight loss in older adults: a systematic review and meta-analysis. Nutr Rev. 2016;74(3):210-224. doi.org/10.1093/nutrit/nuv065
4. Deller M, et al. Effects of calorie restriction with and without strength, endurance or mixed training on fat-free and skeletal muscle mass in overweight or obese individuals: a systematic review with pairwise and network meta-analysis. Diabetes Obes Metab. 2026;28(8):6810-6823. doi.org/10.1111/dom.70873
5. Greendale GA, et al. Changes in body composition and weight during the menopause transition. JCI Insight. 2019;4(5):e124865. doi.org/10.1172/jci.insight.124865