(NEXSTAR) – New injectable drugs like Ozempic, Wegovy, Mounjaro and Zepbound have grown extremely popular with people seeking to lose weight. They’re so in demand that most varieties are listed in short supply by the Food and Drug Administration – and that may be the case for the foreseeable future.

Eli Lilly, the pharmaceutical company behind Zepbound and Mounjaro, told NBC News supply issues could last into 2025.

“It is the demand that’s causing this. We are working so hard every day to make sure that we increase that capacity as fast as we can to get these medications in patients’ hand,” Rhonda Pacheco, Eli Lilly’s group vice president for diabetes and obesity, said in an interview with NBC.

Zepbound and Mounjaro are the same drug, tirzepatide, but they are marketed under two different names. Zepbound is FDA-approved to treat obesity, while Mounjaro is approved to treat diabetes.

Almost all dosages of both brand names are listed as “currently in shortage” by the FDA. Only one dosage size is listed as “available.”

Wegovy and Ozempic are in a similar situation. Both medications are the same drug, called semaglutide, and manufactured by Novo Nordisk. Wegovy is approved for weight loss, and Ozempic is for diabetes.

While Ozempic is listed as available by the FDA, all but one dosage size of the weight loss version Wegovy is in a shortage.

Pacheco told NBC News the limited availability of the Eli Lilly drugs is hard to project far down the line, but the shortages were expected to last “for the near term.” The company plans to open a new facility to ramp up production by the end of the year.

Novo Nordisk said in January it was also working to rapidly ramp up the supply of its lower doses of Wegovy, allowing more new patients to start taking the drug. “However, it’s important to be aware that overall demand will continue to exceed supply which means that some patients may still have difficulty filling Wegovy prescriptions,” the company said.

As shortages continue, both companies advise patients check with local pharmacies every few days and get their refills about one week ahead of time. Novo Nordisk says patients should be specific about exactly what dosage strength they need when asking about availability. If patients aren’t able to obtain the drug, they should talk to their doctor for help with continuing treatment.

Even if you can get your hands on a prescription for one of these in-demand weight-loss drugs, you may have trouble affording it. A month’s supply costs around $1,000 without insurance.