Published on November 19, 2025
Why Weight Loss Can Stall on GLP-1 Medications and What to Do About It
GLP-1 medications like Ozempic, Mounjaro, Wegovy, and Zepbound have become some of the most publicized medications in recent years. Originally developed to help people manage Type 2 diabetes, these medications have gained popularity for their ability to improve blood sugar control, reduce appetite, and promote steady weight loss.
Yet many people find that after the first few months, progress slows or stops altogether.
“GLP-1 medications are powerful tools, not magic bullets. They can make healthy choices easier, but they don’t rewrite physiology,” says Soohan Mansuri, MD, a board-certified primary care physician with the Torrance Memorial Physician Network.
Understanding why weight loss can stall can help set realistic expectations and guide the right adjustments.
How GLP-1 Medications Work
GLP-1 receptor agonist medications mimic a hormone naturally produced in your gut called glucagon-like peptide-1 (GLP-1). This hormone helps regulate blood sugar, slows how quickly food leaves your stomach, and sends satiety signals to your brain so you feel full sooner and stay full longer. When combined with a healthy diet and lifestyle, GLP-1s can lead to significant weight loss, with some studies showing up to 15% of body weight. Still, individual responses vary widely.
As Dr. Mansuri notes, “Success still depends on the same fundamentals: energy balance, muscle preservation, and how your metabolism adapts over time.”
GLP-1s support behavior change, but they do not replace the biological realities of weight loss.
Reasons You Might Not Be Losing Weight
- You’re Not on the Optimal Dose
Most GLP-1 medications are started at a low dose and slowly increased over time to minimize side effects like nausea, vomiting, and stomach pain. It can take several months to reach an optimal dose and noticeable weight loss might not begin until then. If your appetite or weight haven’t changed much, it could be a sign that your dose needs to be adjusted under your doctor’s supervision.
“Some patients don’t see meaningful appetite changes until they reach their steady-state dose,” says Dr. Mansuri. “Titration takes time, and the body adapts at its own pace.”
-
Eating Fewer Meals, But Not Fewer Calories
It’s common to eat less often while on a GLP-1 because of decreased hunger. Yet less frequent or smaller meals don’t always mean fewer calories. Calorie-dense foods high in fats or sugars like cheeses, sugary drinks, creamy sauces, highly processed snacks, or restaurant meals can sneak in more calories than you may realize.
“Eating less often doesn’t guarantee eating fewer calories. Appetite is lower, but calorie density matters more than ever,” warns Dr. Mansuri.
Tracking your food intake for a week or meeting with a registered dietitian can help reveal patterns you might not notice.
“People think slowdowns mean the medication stopped working, but often it’s normal metabolic adaptation,” says Dr. Mansuri. “The body becomes more efficient at lower weights.” Your body is designed to protect itself from perceived starvation. As you lose weight, your metabolism naturally slows down, meaning your body burns fewer calories at rest. This phenomenon, called metabolic adaptation, can make continued weight loss harder over time. Building and maintaining muscle can help keep your metabolism active.
-
Too Little Protein and Strength Training
When people lose weight quickly, part of that loss can come from muscle. GLP-1 medications suppress appetite, which can lead to eating less protein overall. Without adequate protein, the body breaks down muscle as well as fat, which in turn lowers your metabolism even more. Aim for lean protein at each meal and resistance exercise two to three times per week.
“The goal is fat loss, not muscle loss,” says Dr. Mansuri “Without intentional protein intake and resistance exercise, muscle mass declines – and so does metabolism.”
-
Healthy Lifestyle Habits Are Still Important
“GLP-1s work best when the basics are optimized,” Dr. Mansuri says. Even with GLP-1 medications, lifestyle habits remain the foundation of weight management and are essential components in your weight loss journey. GLP-1 medications can make it easier to change habits, but they shouldn’t replace them.
“These medications delay stomach emptying. Without enough fiber, constipation and bloating get worse, which can mask fat loss and make people like feel like they’re not progressing,” Says Dr. Mansuri.
- A balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats enhances results. While appetite suppression helps reduce intake, food quality still matters and eating nutrient-dense foods promotes satiety and overall health.
- Resistance training that incorporates, for example, free weights, weight machines, resistance bands, or your own body weight, builds and preserves lean muscle and boosts metabolism.
- Cardio, such as brisk walking, cycling, or swimming supports calorie burn and heart health.
- Hydration helps digestion, supports fiber, and reduces mistaking thirst for hunger.
-
Other Health Conditions or Medications
Certain medical conditions, such as hypothyroidism, polycystic ovarian syndrome (PCOS), or insulin resistance can make weight loss more challenging. Additionally, medications like antidepressants, antipsychotics, or corticosteroids may slow weight loss progress. If you believe there might be an underlying factor, talk to your doctor before assuming the GLP-1 isn’t working.
A common source of disappointment and frustration is expecting quick results. Social media often highlights dramatic before-and-after photos, but results vary widely. Most people on a GLP-1 often see more gradual and steady declines. Below is the time frame and average percent body weight loss that is typically seen:
Not everyone will experience dramatic weight loss, and that’s normal. Some people see greater benefits in blood sugar control, lower blood pressure, and reduced cravings, which are all meaningful health outcomes beyond the scale.
“Redefine success beyond a weight number,” Dr. Mansuri reminds patients. “Improved blood pressure, blood sugar, energy, and fewer cravings are metabolic victories-even before dramatic weight changes.”
If your weight is not moving as much as you hoped, here are some strategies to try:
-
Prioritize high-quality foods: Eat lean proteins (lean meats, eggs, low-fat dairy products, nuts, soy, beans/peas/lentils, and fish), fruits, vegetables, whole grains, and heart-healthy fats. Make sure you're getting around 20–30 grams of protein each meal.
-
Focus on non-scale wins: Improvements in your biomarkers, energy, mood, and clothing fitting better can be a more complete picture of your progress.
Written by Noel Le, RDN, CNSC, Torrance Memorial Registered Dietitian and Kimberly Gardner, Dietetic Intern
