GLP-1 medications are the latest tool weight loss for many people. One in eight (13%) American adults have tried the medications, and about 6% are currently taking them. Primary care physician Eva Varoqua, MD, answered our questions about how they work and what’s on the horizon for these medications.

How do GLP-1s work to cause weight loss?
GLP-1, or glucagon-like peptide-1, is a hormone that plays a significant role in regulating appetite and glucose metabolism. These medications mainly work in the following ways: 

• Appetite Suppression: GLP-1 helps regulate appetite by acting on the brain. They promote feelings of fullness and satiety, which helps reduce overall food intake. It does this by signaling the brain to reduce hunger and increase the sensation of being full.  
• Slowing Gastric Emptying: GLP-1 slows down the rate at which food leaves the stomach and enters the small intestine. This slower gastric emptying helps prolong the feeling of fullness and prevents rapid spikes in blood sugar levels. 
• Improving Insulin Sensitivity: GLP-1 enhances insulin release in response to meals and improves the body's sensitivity to insulin. Better insulin sensitivity helps manage blood sugar levels more effectively, which can contribute to weight management. 
• Reducing Glucagon Secretion: GLP-1 inhibits the secretion of glucagon, a hormone that increases blood sugar levels by promoting the release of glucose from the liver. By reducing glucagon levels, GLP-1 helps keep blood sugar levels stable. 

Which of the GLP-1s are now explicitly approved for weight loss?
As of 2024, three GLP1 agonists have been approved for weight loss. They are Semaglutide (Wegovy), which is a similar medication to Ozempic, which is mainly used in diabetic patients, as well as Tirzepatide (Zepbound) and Liraglutide (Saxenda).  

The cost of these branded medications can be high. Are compounded versions a safe, effective alternative?
While compounded versions are a cheap and sometimes effective alternative to these pricey drugs, they still come with many risks. Compounded medications are made by third parties that have access to the medically active molecule. However, these may not work the same as the brand names have specific formularies that get the results they do. Because these are compounded or made separately, they are not subject to the same quality control measures as typical medications. The dose you receive may be different from what's actually in the compound. The risks and side effects of the compound are not as well researched as those of the brand-name medications.  

What can patients taking weight loss medications expect?
The first thing I tell my patients is that the journey toward weight loss is a marathon, not a sprint, and starting these medications is just one prong of a multi-faceted approach. Weight loss may be slow initially, and you usually see the benefits a few weeks after being on these medications when your dose is increased. 

The most common side effects are nausea, stomach upset and some constipation. Most of these side effects improve after the first few times you take the medication. Your primary care physician will also be with you every step of the way, and we will check in regularly to see how you do along the way.  

What's on the horizon with GLP-1s?
The world of GLP1s is moving fast, and many aspects are improving. One of the qualms about GLP1s is that they involve a weekly injection, and some people do not like needles. There are oral versions of these medications, but they are not yet approved for weight loss. 

Ozempic, the drug that started it all, has an oral version called Rybelsus. It is the same medication, but instead of a weekly injection, it is taken as a once daily tablet. Tirzepatide (or Mounjaro) is currently being researched as an oral formulation and may be available soon. 

What else do you want people to know about GLP-1s?
GLP1s are just one of the tools that we use to help people on their weight loss journeys. Don't get discouraged if you don't see results right away. Keep working towards your goal; your primary care physician will be happy to help you achieve a healthier version of yourself in any way they can.


Eva Varoqua, MD, Lexington Family Practice White Knoll