FDA just approved Eli Lilly's new weight-loss drug that's cheaper than Wegovy — and stronger, too

• The FDA just approved a new injectable weight-loss drug from Eli Lilly.
• It's called Zepbound, but the medication inside is the same as Mounjaro for diabetes (tirzepatide).

A new injectable drug for weight loss is here, and it may be more powerful than Wegovy.

On Wednesday, the FDA announced that the drug tirzepatide, which is currently available for Type 2 diabetes patients as "Mounjaro" is now approved to treat obesity and overweight, too.

"Obesity and overweight are serious conditions that can be associated with some of the leading causes of death such as heart disease, stroke, and diabetes," Dr. John Sharretts, the director of the Division of Diabetes, Lipid Disorders, and Obesity at the FDA's Center for Drug Evaluation and Research, said in a release.

"In light of increasing rates of both obesity and overweight in the United States, today's approval addresses an unmet medical need."

Tirzepatide vs. Wegovy and Ozempic

Tirzepatide works by mimicking two hormones that are important in regulating hunger. Glucagon-like peptide-1 (GLP-1) is the same hormone mimicked by Ozempic. Tirzepatide also has another hormone-mimicker in it called glucose-dependent insulinotropic polypeptide in it (GIP), which is why it's sometimes called a "twincretin" drug.

"We can consider these like two sister hormones that are in the body that work synergistically," Dr. Nadia Ahmad, the medical director for obesity medical development at Eli Lilly, told Insider earlier this year. "Both of them together work better than either one alone."

These hormones are active in both the belly and the mind. They make food physically stick around longer in a person's stomach, and also help quiet hunger signals in their brain.

In clinical trials, tirzepatide was a stronger drug than semaglutide, the active ingredient in Ozempic and Wegovy. Tirzepatide helped non-diabetic patients with overweight and obesity lose upwards of 15 to 20% of their body weight. Semaglutide helps people with obesity and overweight lose, on average, closer to 15% of their weight.

But some patients Insider has spoken with after using tirzepatide said the dual-acting drug felt too strong, and that they lost nearly all motivation to consume food, struggling to eat enough to maintain the energy to get through the day.

Cheaper per month

Wegovy costs around $1,349 per month without insurance, as Insider previously reported. (Ozempic costs less, at a list price of $936, but it is not approved for weight loss.)

Per Eli Lilly, a Zepbound prescription will be $289 cheaper than Wegovy, with a list price of $1,059.87 for a month's supply. Executives at Eli Lilly said on Wednesday, shortly after the drug was approved, that Zepbound should be available at pharmacies nationwide after Thanksgiving.

"Quite simply, access for anti-obesity medications aren't good enough," Eli Lilly's President for Diabetes and Obesity, Mike Mason, told reporters on a call Wednesday afternoon. "We decided to take a 20% discount to the main competitor, semaglutide 2.4 [Wegovy], really, in order to expand the class."

Eli Lilly's next drug — "Triple G" — may be the real "king kong" for weight loss

Eli Lilly is also at work on an even more powerful "triple-G" drug which some experts are already dubbing the "king kong" for weight loss.

In clinical trials, retatrutide has performed on par with bariatric surgery, with weight loss averages upwards of 24%.

"There's not one therapy that's an answer to everyone's obesity," Ahmad said. "People deserve that individualized treatment. Different therapies for different people."