GLP-1 Therapy Explained: Weight Loss, Diabetes Management, Side Effects, and What to Expect

Featured Expert: Dr. Sachin Kukreja, DFW Bariatrics and General Surgery

GLP-1 therapy has quickly become one of the most talked-about medical treatments in weight loss, diabetes management, and metabolic health. Medications commonly associated with this category include semaglutide, liraglutide, dulaglutide, exenatide, and tirzepatide, known by brand names such as Ozempic, Wegovy, Rybelsus, Trulicity, Victoza, Bydureon, Mounjaro, and Zepbound.

In this Best Docs Network feature, Dr. Sachin Kukreja of DFW Bariatrics and General Surgery helps explain what GLP-1 therapy is, how it works, who may benefit, what side effects patients should understand, and what realistic expectations look like.

What Is GLP-1?

GLP-1 stands for glucagon-like peptide-1. It is a hormone naturally released in the body after eating. GLP-1 helps regulate blood sugar, supports insulin release when glucose levels are elevated, slows stomach emptying, and sends fullness signals to the brain. GLP-1 receptor agonists are medications designed to mimic or enhance those effects.

Although GLP-1 medications may feel new because of their recent popularity, the science has been developing for decades. The first GLP-1 receptor agonist, exenatide, was approved by the FDA in 2005 for type 2 diabetes. Since then, this category has expanded into newer medications used for diabetes, obesity, cardiovascular risk reduction, and, in some cases, sleep apnea related to obesity.

How GLP-1 Therapy Works

GLP-1 medications work through several pathways at once. They may help the body release insulin when blood sugar is high, reduce glucagon signaling, slow digestion, and decrease appetite. For many patients, this combination can make it easier to eat smaller portions, feel full sooner, and improve blood sugar control.

This is why GLP-1 therapy is often discussed in two major settings: type 2 diabetes management and medical weight loss. Some GLP-1 medications are FDA-approved for diabetes, some are approved for chronic weight management, and some have overlapping metabolic benefits. It is important to know that not every medication in this class is approved for the same purpose.

Who May Be a Candidate for GLP-1 Therapy?

A patient may be considered for GLP-1 therapy if they have type 2 diabetes, obesity, or overweight with a weight-related medical condition such as high blood pressure, high cholesterol, or type 2 diabetes. For chronic weight management, the FDA has approved certain medications for adults with obesity, generally defined as a BMI of 30 or higher, or overweight, generally defined as BMI 27 or higher, with at least one weight-related condition.

GLP-1 therapy may be especially useful for patients who have struggled with weight despite diet and exercise, patients with type 2 diabetes who need improved blood sugar control, or patients who need a medically supervised approach to obesity care.

However, GLP-1 therapy is not for everyone. A qualified healthcare professional should review a patient’s medical history, current medications, weight history, lab results, family history, and treatment goals before prescribing.

How Much Weight Can You Lose With GLP-1 Therapy?

Weight loss varies from person to person. It depends on the specific medication, dosage, consistency, nutrition, physical activity, underlying health conditions, and whether the medication is combined with a structured medical weight loss plan.

In a major clinical trial of once-weekly semaglutide 2.4 mg for adults with overweight or obesity, participants lost an average of about 14.9% of their body weight over 68 weeks when combined with lifestyle intervention.

Tirzepatide, a related medication that activates both GIP and GLP-1 receptors, has also shown significant weight loss results and is FDA-approved for chronic weight management under the brand name Zepbound. The FDA approval notes that Zepbound is intended to be used along with a reduced-calorie diet and increased physical activity.

The key point: GLP-1 therapy is not a “magic shot.” It is a medical tool. The best results usually come when the medication is paired with nutrition guidance, strength training, follow-up care, and a long-term plan for maintaining progress.

Common Side Effects of GLP-1 Medications

The most common side effects are gastrointestinal. These may include:

Nausea, vomiting, diarrhea, constipation, stomach discomfort, bloating, reflux, reduced appetite, and fatigue.

For many patients, side effects are most noticeable when starting the medication or increasing the dose. This is one reason medical supervision matters. A clinician can help adjust the dose schedule, review hydration, monitor symptoms, and determine whether the medication remains appropriate.

More serious but less common risks may include pancreatitis, gallbladder problems, dehydration-related kidney issues, severe gastrointestinal reactions, allergic reactions, and low blood sugar when used with certain diabetes medications such as insulin or sulfonylureas. Wegovy prescribing information notes that severe gastrointestinal reactions can occur and that the medication is not recommended in patients with severe gastroparesis.

Patients should seek medical attention for severe abdominal pain, persistent vomiting, signs of dehydration, symptoms of low blood sugar, allergic reaction symptoms, or any concerning change after starting therapy.

Who Should Be Cautious With GLP-1 Therapy?

Patients should talk with their doctor before using GLP-1 medications if they have a history of pancreatitis, gallbladder disease, severe gastrointestinal disease, kidney problems, diabetic retinopathy, or are pregnant, planning pregnancy, or breastfeeding.

Many GLP-1 and related medications also carry a warning about thyroid C-cell tumors based on animal studies. These medications are generally not recommended for patients with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2.

Will GLP-1 Therapy Cause Muscle Loss?

One of the biggest questions around GLP-1 therapy is whether the weight loss comes from fat, muscle, or both.

Any significant weight loss can include some loss of lean mass. That is not unique to GLP-1 medications. Research shows that GLP-1 therapies often produce large reductions in fat mass, while lean mass may also decrease to a smaller degree. A 2025 review noted that clinical trials have shown major fat loss with smaller but measurable decreases in lean mass, making muscle preservation an important part of treatment planning.

This is why patients using GLP-1 therapy should not simply “eat less” without a strategy. A smart plan should include adequate protein intake, resistance training, hydration, sleep, and regular follow-up. The goal is not just a lower number on the scale. The goal is healthier body composition, improved metabolic health, and sustainable weight management.

How Do You Get Access to GLP-1 Therapy?

GLP-1 medications require a prescription. The process usually begins with a medical evaluation. A healthcare provider may review BMI, weight-related conditions, A1C or blood sugar history, current medications, prior weight loss attempts, contraindications, and insurance requirements.

Access can vary based on whether the medication is being prescribed for diabetes, obesity, cardiovascular risk reduction, or another approved indication. Insurance coverage may also differ significantly between plans. Some patients may need prior authorization, documentation of medical necessity, or proof of previous lifestyle-based weight loss efforts.

Because of cost, medication shortages, side effects, and long-term planning, it is important to work with a qualified medical provider instead of trying to obtain these medications without proper supervision.

GLP-1 Therapy and Bariatric Care

For some patients, GLP-1 therapy may be part of a larger obesity treatment plan. For others, bariatric surgery, endoscopic procedures, nutrition counseling, or a combination approach may be more appropriate.

Dr. Sachin Kukreja and the team at DFW Bariatrics and General Surgery provide comprehensive obesity care, including medication-based options, diet counseling, non-surgical solutions, and surgical weight loss procedures. Dr. Kukreja is board-certified in obesity medicine and fellowship-trained in minimally invasive and bariatric surgery.

The Bottom Line

GLP-1 therapy has changed the conversation around obesity, diabetes, and metabolic health. These medications can help many patients reduce appetite, improve blood sugar control, and achieve meaningful weight loss. But they work best when they are prescribed appropriately, monitored carefully, and paired with long-term lifestyle support.

If you are considering GLP-1 therapy, talk with a qualified healthcare professional about your medical history, goals, risks, and options. The right treatment plan should be personalized, realistic, and focused on long-term health — not just short-term weight loss.

Watch the full Best Docs Network interview with Dr. Sachin Kukreja to learn more about GLP-1 therapy, weight loss expectations, side effects, and how patients can make informed decisions about their health.

Medical Disclaimer: This article is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional or physician regarding any medical concerns, conditions, or treatment options. The information provided is not intended to diagnose, treat, cure, or prevent any disease. Any decisions about medication or treatment should be made with a licensed medical professional.