How do GLP-1s work?
Learn all about how these medications affect your body and produce powerful weight loss.
GLP-1s may seem like wonder drugs that popped up out of nowhere, but the reality is they’ve have been around for over twenty years, treating type 2 diabetes since 2005. And while we learn more about them every day in terms of what they can do, we have a pretty solid understanding of how they work for weight loss.
What is a GLP-1?
GLP-1 — which stands for glucagon-like peptide — is a gut hormone released by specialized cells in your intestinal tract after you eat.
“When you consume carbohydrates, GLP-1 boosts the amount of insulin the body makes in order to bring your blood sugar back to normal,” says Dr. Robert Kushner, M.D., professor of medicine in endocrinology and medical education at Northwestern University Feinberg School of Medicine in Chicago.
It does this in two ways: by triggering extra insulin, a hormone that helps lower blood sugar levels, and by inhibiting glucagon, a hormone that raises blood sugar levels.
While GLP-1 naturally occurs in the body, it only lasts about two to three minutes upon release. But the drug form of GLP-1, known as GLP-1 agonists, can last up to 14 hours in your body — so the effects last a lot longer too.
How do GLP-1s help with weight loss?
“GLP-1 agonists activate the receptors in the body that respond to GLP-1,” says Kushner. In other words, they act like the body’s GLP-1. By activating receptors in the pancreas, they’re able to regulate insulin and control blood sugar. But they also activate receptors in the brain to curb appetite and in the gut to slow stomach emptying.
That’s why, notes Kushner, “when a person uses a GLP-1 agonist, they may feel less hungry, have less cravings and thoughts of food, and feel more full after a meal and between meals.” They may also raise your resting metabolism.
Altogether, this leads to weight loss — an average of 15% to 21% body weight, per studies on semaglutide and tirzepatide published in the The New England Journal of Medicine.
It’s important to note, says Kushner, that “the drugs only work while they are taken.” They are designed to be used long-term — not as quick fixes. And they work best when paired with changes in diet and physical activity, especially strength training. The GLP-1 Success Program was created to help you build these healthy habits.