Mounjaro and Rybelsus are both medications approved for treatment if you are living with Type 2 diabetes. Rybelsus was approved in 2020 and Mounjaro in 2023 for Type 2 diabetes, and then again for obesity as well. Rybelsus is not currently available as a treatment for obesity.
Mounjaro and Rybelsus are GLP-1 receptor agonists, which are medications that reduce your appetite to support weight loss and to improve blood glucose control through various mechanisms. Mounjaro, in addition to being a GLP-1 medication, is also a glucose-dependent insulinotropic polypeptide (GIP) mimetic.
GIP is a hormone in your body that supports blood glucose levels and helps your fat cells store more excess energy which we might consume in our diets. GIP is also believed to lower your hunger level because GIP receptors are in the brain’s appetite control center, the hypothalamus, similar to GLP-1.
Therefore, Mounjaro has a dual function that mimics two hormones in your body that support both blood glucose levels and weight loss. Mounjaro is actually more effective for weight loss and blood sugar improvement than Rybelsus.
So, if you are looking for a medication to help you lose weight and improve your blood sugar levels, Mounjaro will lead to more weight loss and blood sugar reductions. However, responses to medications vary between individuals.
How Do Mounjaro and Rybelsus Work?
When you eat, your gut releases hormones that help your body regulate hunger and blood sugar levels. GLP-1, glucagon-like peptide-1, and GIP, glucose-dependent insulinotropic polypeptide, are two of these hormones.
GLP-1 improves insulin function, lowering blood sugar levels and delaying gastric emptying, decreasing appetite. It also communicates with the brain’s appetite control center, the hypothalamus, to lower hunger and food-seeking behavior.
Both Rybelsus and Mounjaro mimic the actions of the hormone GLP-1 and are known as GLP-1 receptor agonists.
GIP is a hormone also released in response to food that helps regulate blood sugar levels and helps your fat cells absorb more excess energy, which then prevents fat from being stored in the liver or pancreas. GIP also communicates with the brain and lowers hunger and food-seeking behavior, similar to GLP-1.
Which is Better?
* Effectiveness- Mounjaro is a more effective drug than Rybelsus. Tirzepatide, the active ingredient in Mounjaro, leads to more significant weight loss and blood sugar reductions than oral semaglutide, the active ingredient in Rybelsus. If you are researching GLP-1 medications for weight loss or blood sugar improvements, Mounjaro would be a better choice.
* Side effects and safety- Every medication has side effects, especially if you have other health conditions.
Some might be mild but uncomfortable, such as cramping, and others can be more severe, such as shortness of breath. You should report any side effects experienced to your doctor and healthcare team.
The side effect profiles of Mounjaro and Rybelsus are similar. The most common side effects for both medications are GI-related, such as nausea, diarrhea, and vomiting, with about 20% of participants experiencing these side effects at least once and around 60-75% of patients on these medications experiencing at least one adverse side effect. One study showed that 3% of patients on Rybelsus experienced a severe adverse side effect, compared to 5.7% on Mounjaro.
Severe adverse side effects are defined as those that interfere with your daily activities, are usually intolerable, and can lead to the termination of the medication.