There’s a class of type 2 diabetes drugs that not only improves blood sugar control but may also lead to weight loss. This class of drugs is commonly called glucagon-like peptide 1 (GLP-1) agonists. A second class of drugs that may lead to weight loss and improved blood sugar control is the sodium glucose cotransporter 2 (SGLT-2) inhibitors. These include canagliflozin (Invokana), ertugliflozin (Steglatro), dapagliflozin (Farxiga) and empagliflozin (Jardiance).

Weight loss can vary depending on which GLP-1 drug you use and your dose. Studies have found that all GLP-1 drugs can lead to weight loss of about 10.5 to 15.8 pounds (4.8 to 7.2 kilograms, or kg) when using liraglutide. Studies found people using semaglutide and making lifestyle changes lost about 33.7 pounds (15.3 kilograms) versus 5.7 pounds (2.6 kilograms) in those who didn’t use the drug.

Diabetes drugs in the GLP-1 agonists class are generally taken by a shot (injection) given daily or weekly and include:

• Dulaglutide (Trulicity) (weekly)
• Exenatide extended release (Bydureon bcise) (weekly)
• Exenatide (Byetta) (twice daily)
• Semaglutide (Ozempic) (weekly)
• Liraglutide (Victoza, Saxenda) (daily)
• Lixisenatide (Adlyxin) (daily)
• Semaglutide (Rybelsus) (taken by mouth once daily)

These drugs mimic the action of a hormone called glucagon-like peptide 1. When blood sugar levels start to rise after someone eats, these drugs stimulate the body to produce more insulin. The extra insulin helps lower blood sugar levels.

Lower blood sugar levels are helpful for controlling type 2 diabetes. But it’s not clear how the GLP-1 drugs lead to weight loss. Doctors do know that GLP-1s appear to help curb hunger. These drugs also slow the movement of food from the stomach into the small intestine. As a result, you may feel full faster and longer, so you eat less.

Along with helping to control blood sugar and boost weight loss, GLP-1s and SGLT-2 inhibitors seem to have other major benefits. Research has found that some drugs in these groups may lower the risk of heart disease, such as heart failure, stroke and kidney disease. People taking these drugs have seen their blood pressure and cholesterol levels improve. But it’s not clear whether these benefits are from the drug or the weight loss.

The downside to GLP-1 drugs is that all but one has to be taken by a shot. And, like any drug, there is a risk of side effects, some serious. More common side effects often improve as you continue to take the drug for a while.

Some of the more common side effects include:

• Nausea
• Vomiting
• Diarrhea

Low blood sugar levels (hypoglycemia) are a more serious risk linked to the GLP-1 class of drugs. But the risk of low blood sugar levels often only goes up if you’re also taking another drug known to lower blood sugar at the same time, such as sulfonylureas or insulin.

The GLP-1 class of drugs isn’t recommended if you have a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia. Lab studies have linked these drugs with thyroid tumors in rats. But until more long-term studies are done, the risk to humans isn’t known. They’re also not recommended if you’ve had pancreatitis.

The drugs already discussed are indicated in people living with type 2 diabetes. There is also a drug that has a higher dose of liraglutide (Saxenda) that’s approved for the treatment of obesity in people who don’t have diabetes.

Semaglutide belongs to a class of medications known as glucagon-like peptide-1 receptor agonists, or GLP-1 RAs. It mimics the GLP-1 hormone, released in the gut in response to eating.

One role of GLP-1 is to prompt the body to produce more insulin, which reduces blood sugar (glucose). For that reason, health care providers have used semaglutide for more than 15 years to treat Type 2 diabetes.

But GLP-1 in higher amounts also interacts with the parts of the brain that suppress your appetite and signal you to feel full. When used in conjunction with diet and exercise, it can cause significant weight loss — and a reduced risk of cancer, diabetes and heart disease — in people who are obese or overweight.

There have been several anti-obesity medications that help suppress appetite and achieve weight loss. But semaglutide performs on a new level.

An early study of 2,000 obese adults compared people using semaglutide plus a diet and exercise program with people who made the same lifestyle changes without semaglutide. After 68 weeks, half of the participants using semaglutide lost 15% of their body weight, and nearly a third lost 20%. Participants who incorporated only lifestyle changes lost about 2.4% of their weight.

Since then, additional studies have shown similar results. But they’ve also revealed that participants tend to regain the weight lost when they stop taking semaglutide.

Semaglutide and tirzepatide are Food and Drug Administration (FDA)-approved medications used to help type 2 diabetes patients manage blood sugar levels. However, doctors also prescribe these medications to individuals with obesity.

Semaglutide is sold under the brand names Wegovy, Ozempic, and Rybelsus. Mounjaro is the brand name for the drug tirzepatide.

Mounjaro (tirzepatide) is an injectable that recently received FDA approval for obesity under the Fast Track designation. This drug may help decrease food intake while also keeping metabolism steady.

Studies on Mounjaro for weight loss have shown that nearly 75% of clinical trial participants lost at least 20% of their body weight. However, it is important to note that the participants took Mounjaro for diabetes, not exclusively for weight loss.

The drug is a GIP and GLP-1 receptor agonist. Agonists are drugs that activate receptors. In this case, GIP and GLP-1 regulate gut hormones called incretins, which help our bodies know when we feel full.

Ozempic (semaglutide) is an intravenous injection that is FDA-approved to treat obesity and people with chronic weight management struggles. Like Mounjaro, this brand-name drug is a GLP-1 agonist.

In a placebo-controlled study of Ozempic, the drug helped participants lose 12.4% of their body weight. In a similar trial on people with diabetes, participants lost an average of 6.2% of their body weight.