GLP-1 agonists: Diabetes drugs and weight loss

Date Updated: 06/23/2020

Answer Section

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. Another class of medications associated with weight loss and improved blood sugar control is the sodium glucose cotransporter 2 (SGLT-2) inhibitors. These include canagliflozin (Invokana), dapagliflozin (Farxiga) and empagliflozin (Jardiance).

Weight loss can vary depending on which GLP-1 medication you use and your dose. But weight loss may average about 3 to 5.5 pounds (1.5 to 2.5 kilograms, or kg) when using these drugs.

If you're actively trying to lose weight through lifestyle changes and add the use of one of these medications, research has shown that the drugs may lead to around 6 to 9 pounds (2.8 to 4.2 kg) of additional weight loss.

Diabetes drugs in the GLP-1 agonists class include:

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

These medications 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 secrete 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 exactly clear how the GLP-1 drugs lead to weight loss. Doctors do know that GLP-1s appear to help suppress appetite. 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 significant benefits. Research has found that some drugs in these classes of medications may lower the risk of heart disease, including heart failure; stroke; and kidney disease. People taking these drugs have seen improvements in their blood pressure and cholesterol levels, though it's not clear whether these benefits are from the medication or the weight loss.

The downside to GLP-1 drugs is that all but one has to be taken by injection. And, like any medication, there is a risk of side effects, some serious. More common side effects usually improve after you've taken the medication 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 medications. But the risk of low blood sugar levels is usually only increased if you're taking another medication 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. Laboratory studies have linked these drugs with thyroid tumors in rats, but until more long-term studies are completed, the risk to humans isn't known. They're also not recommended if you've had pancreatitis.

The drugs already discussed are designed for people who have type 2 diabetes. There is also a drug that contains 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 doctor.