Tirzepatide, currently known by the brand name Mounjaro, is the newest injectable medication for the treatment of diabetes and obesity. It joins a rapidly advancing class of obesity medications that target specific hormonal receptors in the body. These medications are revolutionizing the medical treatment of obesity, as they are hands down more effective than older medications. In fact, tirzepatide is the most effective obesity medication to date. Let’s examine the weight loss medication phenomenon and the reasons why tirzepatide has the potential to transform the obesity epidemic.
At the time this blog is being written, tirzepatide has not yet been approved by the Food & Drug Administration (FDA) for the treatment of obesity, but it is approved for the treatment of diabetes. There are several FDA-approved weight loss medications (i.e. phentermine, Contrave, Qsymia, Saxdena), but none lead to more than an average weight loss of 10 percent body weight. The only exception is Wegovy (2.4 mg semaglutide), which was approved in 2021 and shows a major leap in efficacy. It produces an average weight loss of 15 percent after one year with a once weekly injection. It targets and boosts a hormone called glucagon-like peptide-1 (GLP-1), which controls weight through the brain and digestive tract. Higher levels of GLP-1 decrease appetite and create a prolonged sensation of satiety after eating. Saxdena and Wegovy also help manage glucose levels, making them effective treatments for diabetes.
Tirzepatide builds on the work of semaglutide. Like semaglutide, it targets the GLP-1 receptor to boost GLP levels. But it also targets a second receptor, GIP (glucose dependent insulinotropic polypeptide). GIP is another hormone released into the digestive tract after we eat, and it appears to regulate weight through receptors in the brain and fat cells. More importantly, GLP-1 and GIP are synergistic and enhance each other’s effects. By combining the action of both hormone receptors, tirzepatide leads to more weight loss overall.
The recently published SURMOUNT trial established the efficacy of tirzepatide. In this phase 3, controlled study, 2,539 people were randomized to receive either tirzepatide (at 5, 10 or 15 mg) or a placebo. After 72 weeks of treatment, the following results were observed:
Once tirzepatide is FDA approved for the treatment of obesity, a good candidate would be an adult with a body mass index greater than 30, or greater than 27 with an obesity-related medical condition (i.e. diabetes, high blood pressure, high cholesterol, sleep apnea). Candidates must be willing and comfortable to use a weekly, injectable medication, and—this is critically important—willing to use the medication on a long-term basis. Obesity is a chronic and relapsing condition, therefore medications like tirzepatide are not designed for short-term use.
Patients with obesity AND diabetes are probably the best candidates for tirzepatide because it targets both conditions and may allow patients to wean off of other diabetes medications, such as insulin, that actually promote weight gain. As stated before, tirzepatide is currently only FDA approved for the treatment of diabetes, but we expect approval for an obesity indication is on its way.
Tirzepatide is a once weekly injection supplied in prefilled pens, without a visible needle. The starting dose is 2.5 mg, which is taken once weekly for a month. The dose can then be increased to 5 mg, also taken for a month. The dose can be further increased by 2.5 mg every month, up to a maximum dose of 15 mg. This process can take up to 20 weeks.
The most common side effects of tirzepatide are gastrointestinal, similar to the side effects of semaglutide. They include nausea, diarrhea, and constipation. Mostly, these side effects are shown to be mild and transient, and occur during the dose-escalation period. In the SURMOUNT study, up to 7 percent of patients needed to stop their treatment due to side effects. Other rare side effects include pancreatitis and gallbladder disease, although the study showed that these were no more frequent with tirzepatide than with the placebo.
Our experience has shown us that patients with obesity do not want to undergo bariatric surgery for weight loss; therefore, alternative options are essential in helping us tackle the obesity epidemic. Tirzepatide is a breakthrough because its remarkable average weight loss of 20 percent or more is significantly higher than any prior medication can produce. We know that health conditions, such as diabetes, high blood pressure and high cholesterol, begin to improve and even resolve when someone loses 10 percent of their body weight. With tirzepatide, the average patient will lose double that amount. Patients in the SURMOUNT study showed improvement in multiple obesity-related comorbidities. Additionally, when you realize that the average weight loss with bariatric surgery—the most effective obesity treatment by far—is around 25 to 30 percent of body weight, tirzepatide’s results are truly impressive.
We expect the main barrier for patients who want to use tirzepatide will be cost. Insurance coverage is expected to be spotty and not universal since insurers have not yet connected the dots when it comes to decreasing overall U.S. healthcare costs by reversing the obesity crisis. Similar medications such as Wegovy carry hefty out-of-pocket monthly expenses (greater than $1,000 per month/more than $12,000 per year). And since tirzepatide is a medication that must be taken indefinitely, it’s simply not sustainable for most patients.
Tirzepatide is best provided by a comprehensive weight loss center that allows patients to work a medical team that is highly-trained in obesity medicine and skilled at managing obesity and its related conditions. Ultimately, a comprehensive program is essential for patients to fully succeed with tirzepatide. Patients must have access to nutrition support, as a licensed dietitian can assist patients with their weight loss journey, helping optimize nutrition and support behavior changes over time. Additionally, a structured exercise routine can further enhance health and weight loss benefits.
Whether used alone, or in combination with a weight loss procedure, the newest class of obesity medications, like tirzepatide, is making a true impact after many years of stagnation in obesity treatment. At True You Weight Loss, we are thrilled to see that new medications, along with less invasive weight loss procedures, are giving patients multiple effective options for obesity treatment, especially for those who don’t want bariatric surgery.
Stay tuned—the True You Weight Loss team will be keeping a close watch on what happens next with this breakthrough medication. Our team will be ready to support patients who are interested in learning more or trying tirzepatide once it is FDA approved for patients with obesity.