GLP-1 medications like semaglutide and tirzepatide have changed weight loss for a lot of people. They quiet food noise, help you feel full sooner and make eating less feel manageable. But there's a question worth asking early: when the scale goes down, what exactly are you losing?

Why muscle loss happens

Any time you eat significantly less, your body uses stored energy, mostly fat, but some muscle too. With GLP-1s, appetite can drop so much that people under-eat protein without realizing it. Add little or no strength training, and the share of weight that comes from muscle can go up.

That matters because muscle isn't just about looking toned. It helps you:

• Keep your metabolism working for you

• Manage blood sugar

• Stay strong, steady and injury-resistant as you age

• Keep weight off after you stop or lower your dose

Five ways to protect your muscle

1. Make protein the first thing on your plate. When your appetite is small, eat protein first. Many clinicians recommend a daily protein target based on your body weight. Ask your care team for yours. Eggs, Greek yogurt, fish, chicken, tofu, lentils and a quality protein shake can all help you get there.

2. Lift something, two to three times a week. Resistance training is the strongest signal you can send your body to keep muscle. Bodyweight moves, bands and weights all work. Start where you are and build slowly.

3. Don't rush it. Faster isn't always better. A steadier pace of weight loss, guided by your clinician, gives your body time to adapt and makes muscle easier to keep.

4. Check your labs. Low vitamin D, thyroid issues, low testosterone and other hormone imbalances can all make it harder to build and keep muscle. A baseline panel before you start, and check-ins along the way, keep your plan on track.

5. Track body composition, not just weight. The scale can't tell fat from muscle. Body composition scans and simple measurements give you a clearer picture of progress.

Where body treatments fit in

Some non-invasive body treatments use electrical muscle stimulation (EMS) to make muscles contract, often paired with treatments aimed at fat. Many people like them for tone and definition during weight loss. Think of them as a complement to strength training and good nutrition, not a replacement.

Medication is one part of the plan

At Sela, GLP-1s are part of a medically supervised program, not a standalone prescription. Every plan starts with a Wellness Exam, with 60+ biomarkers and a one-on-one review, so your medication, nutrition, training and body treatments work together. Learn more about our medical weight loss and programs.

This article is for general education and isn't medical advice. GLP-1 medications require a prescription and medical supervision. Talk with a licensed clinician about whether they're right for you. Individual results vary.