What exactly is Mounjaro? Well, you've probably heard of its more famous cousin, Ozempic, thanks to celebrities who seem to be using it left and right. Developed as diabetes pharmaceuticals and known better by their brand names, namely Mounjaro, Ozempic, Wegovy, Zepbound, and others, these medications have changed the game for many people in their lifelong struggle with weight loss.
Although it might seem that Ozempic and Mounjaro do the same thing (make people lose weight), they're actually different medications. Ozempic is semaglutide, and Mounjaro is tirzepatide. Semaglutide is a GLP-1 receptor agonist that activates hormones to control blood sugar levels (that's why it's primarily a diabetes medication) and reduces appetite.
But Mounjaro is newer and is a two-receptor agonist medication. That basically means that instead of activating just one receptor, the GLP-1, it activates a second one at the same time: the glucose-dependent insulinotropic polypeptide (GIP).
Tirzepatide (a.k.a. Mounjaro) was approved for use in May 2022. Researchers claim that, coupled with regular exercise and a healthy diet, tirzepatide can be prescribed to type 2 diabetes patients. Both semaglutide and tirzepatide are considered huge milestones in the medical field, with the Danish scientist Lotte Bjerre Knudsen receiving the Breakthrough of the Year Award for discovering semaglutide.
Tirzepatide was created by the pharmaceutical company Eli Lilly, with the professor of biochemistry at the University of Indiana, Richard DiMarchi, at the helm. After Knudsen's success in getting semaglutide approved for treating type 2 diabetes in 2017 and obesity in 2021, DiMarchi and his team combined two receptor agonists to create a more effective medication. That led to Mounjaro coming out as a medication to help with diabetes and Zepbound for obesity.
How much weight do people actually lose when they use these medications? According to the medical trials, those who used semaglutide lost about 17-18% of their body weight. With Zepbound, the effects were even more impressive: patients lost up to 20% of their body weight.
Today, scientists at Eli Lilly are developing a receptor agonist that targets three receptors at once. Although it is still in the experimental phase, initial studies have shown that it helps patients lose around 24% of their mean weight.
As with all medications, tirzepatide and semaglutide should be taken with precautions. Assistant Professor of Clinical Medicine at Weill Cornell Medicine, Katherine Saunders, warns that unwanted side effects may appear when the medications have been inappropriately prescribed. "It's critical to start with low doses, and increase only as needed and tolerated. Dose titration must be personalized."
There are other reasons to be cautious about using Mounjaro, as well:
- Technically, it's not a weight loss medication, but it is meant for patients with type 2 diabetes. In the U.S., for example, the FDA has not approved it for weight loss. Zepbound is for people who are overweight or obese and do not have diabetes.
- Not everyone can afford Mounjaro, and using it for weight loss only causes shortages for diabetes patients.
- Both Ozempic and Mounjaro are relatively new medications, so long-term side effects haven't been studied yet. Experts don't know whether a patient will need to take the medication for the rest of their life to keep the weight off. Some patients have been able to retain their Ozempic or Mounjaro results; others have seen their weight bounce back.
These type 2 diabetes and weight loss medications might also have unpleasant side effects. They include:
- Allergic reactions to the skin, tongue, and throat.
- Vision changes.
- Dehydration and thirst.
- Irregular heart activity.
- Problems with one's gallbladder.
- Pancreatitis.
- Thyroid cancer.
- Damage to the kidneys.
- Mild gastrointestinal discomfort (constipation, nausea, upset stomach, etc.).
