Understanding GLP-1s: Peptide Therapy Explained

Mounjaro, Ozempic, Zepbound, Wegovy, Semaglutide, and Tirzepatide?

You've probably heard about these drugs on TV or social media, but what are they? Well, they are all peptides that are being used to help manage diabetes and obesity.

What is a GLP-1?

Ozempic was approved by the FDA in 2017 to treat Type 2 diabetes, and in 2021, it was renamed Wegovy and approved for weight loss. Mounjaro was released in 2022 for treating Type 2 diabetes, and then in 2023, it was rebranded as Zepbound and approved for treating obesity. Both medications have become so popular that they’re in short supply, leading pharmacies to make compouded versions of them. The compounded version of Wegovy is called Semaglutide, and the compounded version of Zepbound is called Tirzepatide.

Semaglutide is a type of drug known as a glucagon-like peptide-1 receptor agonist, or GLP-1 for short. Tirzepatide is a combination drug that works on both the GLP-1 receptor and another receptor called glucose-dependent insulinotropic polypeptide (GIP). This means Tirzepatide acts as both a GLP-1 and GIP.

How does a GLP-1 work?

GLP-1 drugs mimic a hormone called GLP-1 that your intestines release after you eat. This hormone helps control blood sugar, suppresses appetite, slows down digestion, and influences insulin and glucagon release from the pancreas. Taking a GLP-1 drug boosts the hormone’s effects, helping your body control blood sugar and making you feel fuller after eating.

The GLP-1 hormone also triggers insulin release from the pancreas. Insulin is essential because it helps your body use food for energy and prevents excess glucose from being released into your blood. Less glucose in the bloodstream means less fat storage. Another key role of GLP-1 is slowing down how quickly food leaves the stomach. This helps keep your blood sugar stable after eating and makes you feel fuller for longer, reducing hunger.

Tirzepatide, in addition to being a GLP-1, also acts as a gastric inhibitory polypeptide or GIP. GIP is another hormone released after eating, which helps insulin enter your bloodstream and makes your cells more responsive to insulin. This combination of GLP-1 and GIP is particularly helpful for people with insulin resistance.

What is peptide therapy?

For people struggling with obesity, GLP-1 medications can be life-changing. They’ve been shown to be even more effective than weight loss surgery in some cases. These medications are injected once a week into the fatty tissue of the abdomen using a small needle. They mimic the GLP-1 hormones that your body naturally produces, helping you feel full faster and stay full longer. This results in eating less, which leads to weight loss. Additionally, less glucose is released into the bloodstream, so the body stores less fat.