The United States Food and Drug Administration has formally approved tirzepatide for use as a weight loss medication. Tirzepatide is the active ingredient in Mounjaro, the blockbuster type 2 diabetes drug. Eli Lilly, tirzepatide’s manufacturer, announced that the drug would have a new name when sold for obesity: Zepbound.
What does it mean for people with diabetes? It’s tough to know.
For most of 2023, Mounjaro users with type 2 have had to navigate around frustrating shortages, largely provoked by demand for the drug from people without diabetes. The introduction of a new version of tirzepatide exclusively for weight loss will almost certainly provoke even more hype and demand. It will also help convince insurers to begin reimbursing the drug’s cost for weight loss, which will only increase the number of potential customers.
Though Lilly has geared itself up for this moment and is rapidly expanding its manufacturing capacity, people with diabetes can’t be blamed for expecting that the news may only mean more shortages in the future.
The Approval
Zepbound will immediately become what is almost certainly the most effective weight loss drug ever approved. In the SURMOUNT-1 Trial, the largest test of tirzepatide in people with obesity but without diabetes, participants using the highest dosage lost 20.9 percent of their bodyweight over 72 weeks, a result on par with bariatric surgery.
The FDA’s approval, announced on Wednesday, November 8, stated that the drug would be indicated for people with obesity (a body mass index [BMI] of at least 30 kilograms per square meter) or overweight (BMI of at least 27) with at least one weight-related condition, such as high blood pressure or high cholesterol.
An astonishingly large number of people could qualify for this powerful new drug. The United States has over 250 million adults and nearly three-quarters of them are overweight or have obesity, according to the National Institutes of Health. Nearly half of American adults have hypertension. Across the world? Literally billions meet the FDA’s guidelines for treatment with tirzepatide.
A Brief History of Tirzepatide Shortages
Mounjaro has been so popular that its manufacturer has had a tough time keeping up with the demand. The FDA officially added Mounjaro to its drug shortage database in December 2022, and the problem has more or less persisted ever since. In February, Lilly celebrated the end of its first shortage, but the success was temporary. In July, Fierce Pharma reported that the Mounjaro shortage was back and worse than ever.
Recent news suggests that Lilly has mostly caught up — every dosage of the drug is now listed as available in the FDA shortage database — but social media suggests that a huge number of patients are still struggling to find the drug that’s changing so many lives. Forums dedicated to the use of Mounjaro seemingly remain inundated with complaints about shortages and questions about how to handle missed doses.
The FDA’s approval of tirzepatide for weight loss was expected to come, and will not catch Lilly by surprise. The pharmaceutical giant is dramatically increasing its manufacturing capacity, according to CNN, in a “race” to meet demand that just keeps skyrocketing.
But people with diabetes who take Mounjaro can be forgiven for being nervous about supply issues. The new wave of publicity could once again drive more demand for tirzepatide than the maker is capable of meeting. That could again cause patients without diabetes to reach for Mounjaro, just as Wegovy shortages led to Ozempic shortages — taking the drug out of the hands of people with diabetes.
All About Tirzepatide
Zepbound has a new name, but it is chemically identical to Mounjaro and will be sold in the exact same doses. The active ingredient in each medication is tirzepatide, a GIP/GLP-1 receptor agonist.
Tirzepatide may be the most effective type 2 diabetes drug ever developed. As good as semaglutide (Ozempic, Wegovy) is, tirzepatide’s results are better across the board — particularly for weight loss.
In the SURPASS-1 Trial, which tested the new pharmaceutical for 40 weeks in nearly 500 patients with type 2 diabetes, participants experienced the following results:
A1C. Patients who began the trial with an average A1C of 7.9 percent enjoyed A1C reductions of 1.9 to 2.1 percent. At the end of the trial, a strong majority of patients (81-86 percent) saw their A1C fall to below 6.5 percent, outside of the diabetic range. About half of those who used the highest dosage saw their A1C fall to less than 5.7 percent, completely out of the pre-diabetic range.
Fasting Blood Sugar. The average fasting blood sugar of patients declined by 44-49 mg/dL!
Weight loss. Participants lost an average of 15 pounds (at the 5mg dosage) to 21 pounds (at the 15mg dosage).
Cholesterol. Triglycerides and LDL cholesterol both went significantly down; HDL (“good cholesterol”) went significantly up.
People without diabetes lose even more weight and enjoy some of the same metabolic improvements.
Because tirzepatide is so new, we know less about its secondary effects. It is associated with some of the same gastrointestinal side effects for which semaglutide has quickly become infamous, though so far there has been less media buzz about rare issues such as stomach paralysis or mysterious benefits like relief from addictive behaviors.
There is a major long-term cardiovascular outcome trial occurring right now that will assess whether or not tirzepatide has benefits for heart health. If it does, as seems likely, it will only further boost the drug’s reputation with diabetes experts.
Cost
In a press release, Lilly stated that Zepbound would debut with a list price of $1,059.87. Insurance coverage may initially be scanty — insurers have been slow to reimburse the weight loss drug Wegovy — though a new savings card program promises discounts for starter doses.
Despite the intimidating price, we can expect sky-high demand for the drug. Public health experts have lamented the fact that the new weight loss drugs are so out of reach for most Americans in need of them, but that hasn’t yet limited demand. At the moment there is still plenty of room to grow, even if Zepbound will likely be something of a luxury item.