GLP-1 agonists: Diabetes drugs and weight loss

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 GLP-1 drugs can lead to weight loss of about 10.5 to 15.8 pounds (4.8 to 7.2 kilograms, or kg). 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.

If you have diabetes and wonder if one of these drugs may be helpful for you, talk to your diabetes doctor or health care provider.

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