OH - Zempic and More. What's the Scoop With These Weight Loss Drugs?

Dr. Christi Crumpecker
March 17, 2024
5 min read
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What’s with the Weight Loss Shots?

Weekly injectable medications, like Ozempic (semaglutide), have been used to manage diabetes for years. Now they are being marketed for their effect on obesity. These medications are GLP-1 (glucagon-like peptide 1) analogs. They mimic the effects of naturally-occurring GLP-1 hormone in the body, which is released by the intestines when we eat. This hormone’s main action is to stimulate the release of insulin and inhibit glucagon secretion, keeping our blood sugars in a normal range after meals. However, GLP-1 also sends satiety signals to the brain—essentially telling us we are “full” and it’s time to stop eating. Semaglutide (and other GLP-1 analogs) can help us feel satisfied with smaller portions, ultimately leading to an average weight loss of 15-21% for individuals with obesity. As obesity is the most significant modifiable risk factor in deadly conditions like high blood pressure and diabetes, this amount of weight loss can potentially add many healthy years, even decades, to our lives.

There are risks and downsides to the “weight loss shots.” They are often not covered by insurance and are typically in short supply due to their popularity. Ozempic can cost over $1500 per month out-of-pocket. Common side effects include nausea, fatigue, diarrhea, and constipation. More serious but rare side effects—including gastroparesis, inflammation of the pancreas, gallstones, and kidney injury—occur in up to 1% of patients. Rat studies have shown an increased risk of thyroid tumors. 

Weight loss with GLP-1 analogs is usually not extremely rapid—most lose an average of about 5 pounds per month. If a person stops taking the medications, early research indicates that they will regain about 70% of the lost weight in the first year. Unfortunately, we do not have enough experience yet to know the effects of GLP-1s for weight management beyond two years. Manufacturers have suggested that those struggling with obesity consider lifetime use of the medications, but this recommendation has not yet been adequately vetted by the medical community.

Although it may seem counterintuitive, long-term behavior change and nutrition become even more important with medication-assisted weight loss. Because GLP-1s increase satiety and lead to lower food intake for most people, we need to pay even more careful attention to the quality of our meals. This is particularly key for maintaining muscle mass during weight loss. Research has shown that during reduced calorie intake, up to one-third of the weight lost will be muscle. Eating adequate protein is essential for maintaining muscle mass during weight loss; adding physical activity—particularly resistance training—will strengthen the muscle fiber as well, ensuring that the retained muscle functions well. Getting enough high-quality sleep will also enhance satiety, fat loss, and muscle retention, regardless of weight-loss method.

GLP-1s represent an important tool in addressing obesity. Not only may they help individuals avoid the associated health complications, the effects of these medications help us understand obesity as a complex metabolic condition, rather than a moral failing or lack of willpower. Whether or not these (or other) medical weight loss interventions are appropriate depends on the needs, goals, and risk factors of each individual. Regardless of weight loss method, a balanced diet, quality sleep, and adequate exercise will always be the staples of sustainable weight loss and a healthy lifestyle.

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"Novo Nordisk says stopping obesity drug may cause full weight regain in 5 years". Reuters. 30 March 2023.

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