Weight Loss Drugs: Separating Fact From Fiction

April 28, 2025

For many years, patients struggling with weight loss were told that success simply required more willpower – eat less, exercise more and the weight would eventually come off. But recent advances in medical science prove it’s often not that simple.

“We now know significantly more about the chemical and structural changes that occur with excess body weight,” says Leena Khaitan, MD, bariatric surgeon and Director of the Metabolic and Bariatric Nutrition Center at University Hospitals. “These metabolic changes can make it considerably more difficult to lose weight and keep it off.”

The Growing Popularity of Weight Loss Medications

“GLP-1 medications like Wegovy and Ozempic are a relatively new addition to the weight loss toolbox. Their promise of 15-20 percent weight loss is enticing to those who haven’t had success with diet and exercise alone,” says Dr. Khaitan. “Research shows that losing just 5-10 percent of body weight can dramatically improve your health, so losing those extra pounds offers more than just a cosmetic reward. It can also improve or reverse weight-related health conditions like high blood pressure, diabetes, joint pain and sleep apnea.”

But are these medications safe? Do they have side effects? Dr. Khaitan answers some common questions about weight loss medications.

How do weight loss medications work?

Glucagon-like peptide-1 (GLP-1) is a naturally occurring hormone that is released by the intestines after eating and stimulates the pancreas to produce insulin, which lowers blood sugar levels. It also slows down digestion and reduces hunger signals to the brain. People with excess weight or obesity tend to have lower levels of GLP-1.

Medications like Ozempic, Wegovy and Mounjaro bind to GLP-1 receptors in the pancreas, brain and GI tract to mimic the action of the hormone, which:

Decreases appetite and increased feelings of fullness
Delays food leaving the stomach so you feel full longer
Lowers blood sugar levels
Reduces thoughts about food and eating – often referred to as food “noise”

What are the possible side effects?

Although serious side effects are rare, up to 50 percent of people will experience some degree of nausea, constipation or diarrhea while taking these drugs. Some also report side effects like irritability, anxiety and/or sleep problems. More serious side effects that may occur with long-term use include cardiovascular issues, pancreas inflammation, liver damage or gastroparesis, a condition in which the stomach muscles don’t function properly to move food into the intestines.

Short- and long-term use should always be monitored by a healthcare professional to manage side effects and adjust the dosage when necessary.

If I stop taking the medication, will I automatically gain all the weight back?

It is very likely that after stopping weight loss medications there will be some weight regained. Obesity is a chronic disease like hypertension and when the medications are stopped, the condition returns. However, if lifestyle modifications like calorie restriction, healthy eating, regular exercise and other behavioral changes are maintained, it’s unlikely that weight will return to its original level. Talk to your doctor about how to safely taper off the medication and strategies to prevent weight gain.

Are they covered by insurance?

Insurance coverage for weight loss drugs varies widely depending on the specific plan, the type of drug, and the patient's medical history. Commercial providers may require that a patient have a certain body mass index (BMI) and/or an obesity-related health condition like type 2 diabetes or heart disease. Others may require that the patient has tried other weight loss methods like diet and exercise before they will cover weight loss drugs.

Medicare does not generally cover weight loss medications unless they are prescribed to treat a specific medical condition like type 2 diabetes.

Who shouldn’t take weight loss medications?

In general, weight loss drugs may be an option for adults up to age 75. They are not recommended for children, women who are pregnant or breastfeeding and those with certain health conditions like liver or kidney problems.

Are there any potential interactions with other medications?

Yes, weight loss drugs can interact with other medications, supplements and herbal products. As some of these interactions can be dangerous, always tell your doctor about all the medications and supplements you take before starting weight loss drugs.

Weight Loss Drugs Aren’t a Magic Bullet

Significant weight loss is never easy and there is no such thing as a magic bullet for weight loss. It takes permanent lifestyle changes, including diet and exercise, and patience to allow these changes to become a habit. For some, medication is an effective tool and can be used at low doses for maintenance once the goal weight is achieved.

“Losing weight is an intentional effort. Avoiding processed foods that are calorie-dense but nutrient deficient and healthy lifestyle choices are essential to achieve a healthy weight,” says Dr. Khaitan. “To achieve sustainable weight loss, it’s important to take a comprehensive, multi-faceted approach that includes a balanced diet, regular exercise and lifestyle modification.”