Starter doses of the weight-loss drug Zepbound are now available in single-dose vials, drug manufacturer Eli Lilly announced Tuesday, a move the company says will “significantly” expand supply as it sees continued high demand. Instead of a preloaded injector pen, patients will use a syringe to draw out the medicine. Tirzepatide, the active ingredient in Zepbound and Mounjaro, is part of new class of medications used to treat obesity and diabetes that have skyrocketed in popularity, driving shortages — and leading some people to use versions made by compounding pharmacies.

“These new vials not only help us meet the high demand for our obesity medicine, but also broaden access for patients seeking a safe and effective treatment option,” Patrik Jonsson, president of Lilly Cardiometabolic Health and Lilly USA, said in a statement. The new vials will be available exclusively to people who pay out of pocket through LillyDirect, a company platform that helps coordinate telehealth services and fill prescriptions for patients. A four-week supply of 2.

5-milligram (mg) vials is $399, and a four-week supply of 5-mg vials is $529, less than half the list price of other GLP-1 medicines for obesity, according to Eli Lilly. These prices are in line with those offered through Lilly’s savings program for uninsured people, the company said. But the option to pay out-of-pocket for the vials now expands access to patients who aren’t eligible for the savings program, such as those on.