2 Popular Obesity Drugs: Effective Short Term, but Risks of Muscle and Nutrient Loss and Other Serious Side Effects

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The use of prescription drugs for weight loss has been controversial, and it is essential to consult with a doctor before considering their use. Two medications in particular—Wegovy and Ozempic—have skyrocketed in popularity over the last few years. Despite their fame, these medications can have potential risks and side effects that need to be evaluated by a qualified professional.

Wegovy, manufactured by Novo Nordisk from Denmark, has become increasingly popular, with more than 100,000 prescriptions written weekly in the United States. The higher demand has resulted in the company announcing a 50 percent cut in the supply of starter doses. Novo Nordisk has signed up a second manufacturer in the United States to produce Wegovy later this year.

Many celebrities have tried Wegovy or the type 2 diabetes drug Ozempic, including Tesla CEO Elon Musk and Huffington Post co-founder and Thrive Global CEO Ariana Huffington.

Ozempic and Mounjaro, another anti-diabetic medication, have also been sought after by those who want to lose weight. Wegovy was approved for chronic weight management in 2021, and it shares the same active substance, semaglutide, as Ozempic. Semaglutide increases insulin release in response to food and regulates appetite, reducing food intake, hunger, and cravings.

Mounjaro, made by American pharmaceutical company Eli Lilly, has tirzepatide as its active substance, which works similarly to semaglutide by acting as two hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1).

All three medications require weekly injections.

What Doctors Say

Semaglutide and tirzepatide are considered “safe and effective,” Dr. Harold Bays, the medical director and president of the Louisville Metabolic and Atherosclerosis Research Center, told The Epoch Times. “If you look at the clinical trial evidence, what I would say is that both semaglutide and tirzepatide improve not just the weight of patients, but the health of patients.” Bays is also the chief science officer of the Obesity Medicine Association and has contributed to studies related to Wegovy.

A 2021 double-blind study enrolled 1,961 adults with a body mass index (BMI) of 30 or higher. After 68 weeks of receiving weekly semaglutide injections or placebo, along with lifestyle intervention, a little over 86 percent of participants lost at least 5 percent of their body weight, and about half of them lost over 15 percent of their baseline weight. Overall, one-third of the adults treated with semaglutide lost at least 20 percent of their weight. In comparison, that typically occurs one to three years after bariatric surgery.

The study also showed decreased waist circumference, BMI, blood pressure, and blood glucose levels.

Yet some doctors have concerns.

Weight Loss, or Muscle Loss?

Dr. Robert Lustig, director of the Weight Assessment for Teen and Child Health Program at the University of California, San Francisco, pointed out that in the same study, 40 percent of the weight lost was lean mass, and many side effects were reported. Lean mass is the total body weight minus body fat weight. Since the weight of organs, skin, and bones won’t change much, body water and muscle mass are the two significant parts of lean mass to look at during weight loss.

“That’s what starvation does,“ he said recently at the STAT Breakthrough Summit in San Francisco. ”You lose equal amounts of muscle and fat,” he added. “If you’re a person 60 years old or over and you’re losing muscle, your risk of dying just went up exponentially.”

Losing muscle during weight loss is not considered desirable because muscle keeps you strong and fit. In addition, losing muscle can slow metabolism, which means the body will burn fewer calories.

Strength or resistance training can help you maintain muscle mass and increase fat burning. As you gain muscle, the body needs to burn more calories at rest. A study conducted in 2021 (pdf) found that weight training promotes cellular changes that help with burning fat.

Relying Solely on Medication Is Not Healthy

“There is healthy weight loss and unhealthy weight loss,” Dr. Konstantinos Spaniolas, director of the Bariatric and Metabolic Weight Loss Center at Stony Brook University, told The Epoch Times.

While semaglutide and other weight loss medications decrease appetite, simply eating less without proper nutrition could lead to undesirable muscle loss, he added. “In terms of preventing or minimizing muscle loss, high protein intake and exercise combined can work together to improve muscle profile,” he said. “Both aerobic exercise and strength training help preserve muscle during weight loss. Resistance-type workouts also improve muscle performance.” To address obesity and being overweight, Spaniolas stressed the need for a multidisciplinary approach, including nutritional or psychological counseling.

“Overall, the medications are safe,” Spaniolas said. But he noted that they need to be used in the right setting, alongside proper nutritional coaching, for long-lasting benefits.

Bays echoed Spaniolas’ concerns and emphasized that medications should not be the sole means of losing weight. “It should not be assumed that all the effectiveness of managing obesity should be left up to the effects of the drug,” Bays said. “I don’t think that’s the right way to go.”

He also highlighted the importance of a comprehensive approach that includes nutrition, physical activity, behavior modification, and medical therapy. “People have to be ready for change. It isn’t just about a drug,” Bays added, noting that, ultimately, a personalized approach is the most effective way to achieve sustainable weight reduction.

Concerns About Side Effects and How the Medication Works

The 2021 clinical trial revealed a high incidence of gastrointestinal problems—such as nausea, diarrhea, vomiting, and constipation—in just over 74 percent of participants taking semaglutide, compared to nearly 48 percent receiving a placebo.

Some experts reject these drugs entirely due to their side effects and the working mechanism.

Lauren Muhlheim, a certified eating disorder specialist and clinical psychologist, told The Epoch Times that taking these drugs could lead to eating disorders. “They essentially operate on the same mechanism as an eating disorder,” she added, as the drugs work by reducing appetite and causing people to undereat.

As a result, people tend to lose weight because they eat less, not because the drugs magically burn fat, Muhlheim said. In addition, individuals who are not eating enough may binge eat later and are at risk of developing anorexia.

Wegovy and the U.S. Food and Drug Administration (FDA) warn that semaglutide may cause serious side effects, including thyroid cancer (pdf). The FDA recommends that people with a family history of medullary thyroid carcinoma or an endocrine system condition not take Wegovy. Other potentially serious side effects include inflammation of the pancreas, increased risk of low blood sugar, kidney failure, allergic reactions, and depression or suicidal thoughts. In addition to these, more common side effects like nausea, diarrhea, vomiting, constipation, and stomach pain have also been reported.

High Cost and Risks Associated With Regained Weight

Muhlheim cited research indicating that weight loss achieved by taking semaglutide is only temporary. The study, published in 2022 in Diabetes, Obesity and Metabolism, found that people who stopped taking semaglutide regained two-thirds of the lost weight in one year. Furthermore, improvements in cardiometabolic complications, such as type 2 diabetes and high blood pressure, also reversed.

Given the price tag of approximately $1,400 a month and the likelihood that it is not covered by health insurance unless a person has obesity or other medical conditions, Wegovy is likely not accessible for many.

According to a real-world observational study, as opposed to a clinical trial, nearly half of the patients discontinued GLP-1 RA therapy within one year, and almost two-thirds discontinued within two years. However, the study did not provide reasons for the high quitting rates.

In the 2021 clinical trial during which participants were treated with semaglutide for 68 weeks, 7 percent of the group administered the drug discontinued due to adverse effects, compared to 3 percent in the placebo group. The study also found that in real-world settings, only a minority of patients initiating GLP-1 RAs achieved clinically meaningful weight loss, defined as a loss equal to or more than 5 percent of baseline body weight.

Weight fluctuation may also be harmful. A meta-analysis of 14 studies found that individuals who experienced weight cycling had a higher risk of diabetes.

Conflict of Interest

The 2021 study demonstrating the benefits of semaglutide was supported by the drug’s manufacturer, Novo Nordisk. “There’s a lot of conflicts of interest that need to be considered,” Muhlheim said. “People should remember that drug companies are more interested in profit than the health of larger-bodied people and that larger-bodied people are a target for profit.”

The market value of Novo Nordisk has risen by more than 140 percent since the firm launched Wegovy in the United States in June 2021. According to reports, the company is now the second-most valuable company in Europe, trailing only French luxury goods group LVMH. Pfizer and other pharmaceutical companies are developing weight-loss therapies similar to Wegovy, with an eye on a potential $100 billion market share.

Bays, who helped run the 2021 study and has received funds from Novo Nordisk, said that anti-obesity medication clinical trials are often funded by their manufacturers.

“Unless the data is fraudulent, the raw results of these clinical trials would not be expected to change, no matter the funding,” Bays added. He also noted that several anti-obesity medication initiatives had been withdrawn due to safety or efficacy problems, regardless of whether the manufacturer funded the clinical trials.