Obesity drugs often aren't covered by insurance. Experts say this limits access, increases disparities.

Dr. Deborah Horn wants to give her patients with obesity the best possible care. But too often, the conversation in appointments isn't focused on picking the best treatment options, which sometimes includes anti-obesity medication.

Instead, the conversations are focused on cost and insurance coverage.

"When we're sitting in front of a patient and thinking, how can we best help this patient, and if medication is the best route, coverage should really be the last thing we think about," says Horn, the medical director for the UTHealth Houston Center of Obesity Medicine and Metabolic Performance. "Unfortunately, with the state of access, coverage becomes the first thing."

Over 40% of adults in the United States have obesity, which the Centers for Disease Control and Prevention defines as a body mass index of 30 or higher. While body mass index is not an indication of health, obesity is linked with heart disease, stroke, type 2 diabetes and certain types of cancer.

Newer anti-obesity medications like semaglutide (the active ingredient in Wegovy and diabetes medication Ozempic) can be highly effective for people with obesity. But analysis and reports show that drugs used for weight loss aren't often covered by Medicare, most Medicaid programs, and some commercial insurances, limiting access to the drugs — which can cost over $1,300 out of pocket for a month's supply.

"If patients are on Medicare or Medicaid, the conversation is about what patients can manage for themselves financially," Horn says. "That's a frustrating conversation for patients."

As conversations around semaglutide and other similar drugs continue, "Impact x Nightline" explores issues surrounding the drugs, and the effects they're having on patients who have been struggling with weight loss in an episode now streaming on Hulu.

Medicaid coverage for anti-obesity drugs vary state by state. "States have the option, but are not required, to cover weight loss medication," a Centers for Medicare & Medicaid Services spokesperson said in an email to ABC News.

Coverage doesn't map neatly onto obesity rates in states.

"Louisiana, for example, has a pretty high rate of obesity, they cover anti-obesity medication in their Medicaid program," says Timothy Waidmann, a senior fellow in the Health Policy Center at the Urban Institute and author of the report Obesity across America. Colorado's Medicaid program doesn't cover these types of drugs, and they have the second lowest obesity rate in the United states, according to America's Health Rankings.

While Medicare doesn't cover these types of drugs, beneficiaries enrolled in Medicare Advantage plans might have the medications covered.

However, this leaves a majority of Medicare enrollees without coverage for these types of drugs, forcing them to pay high out-of-pocket costs, or go without.

The coverage gaps could deepen economic and racial disparities around obesity, experts say. Patients who can afford to pay out-of-pocket for the drug are the ones who are able to access treatment.

"The biggest struggle we have in clinic is equity in care," Horn says.

Horn, other experts, and obesity advocacy organizations are pushing for Congress to pass the Treat and Reduce Obesity Act, which would (among other things) expand anti-obesity medication coverage for people on Medicare. Horn is a paid consultant for Novo Nordisk.

Right now, coverage of anti-obesity medications by commercial insurance plans is mixed, and often varies by employer to employer, Horn says. But if Medicare covers the drugs, other plans would likely follow, she says. "If we can get Medicare to cover the medications — no one wants to be worse than Medicare," she says.

The success rates of the newer drugs like semaglutide and the new awareness around them might help move the needle and push more commercial insurance and Medicaid programs to cover the medications, experts say.

"I think, broadly, the popularity will only work to increase the number of states that offer coverage," Waidmann says.

Older anti-obesity medications weren't nearly as effective for weight loss as semaglutide and the other newer compounds, like tirzepatide (the active ingredient in diabetes medication Mounjaro), Horn says. They lead to around the same amount of weight loss as bariatric surgery — which Medicare and most Medicaid programs do cover.

"They've closed the gap," Horn says. "We have medications that are as efficacious or almost as efficacious as surgery. Patients should be given a choice."

But for now, patients who could benefit from these medications are stuck in a bind. Horn says she has a patient who lost over 100 pounds on semaglutide, but his insurance recently changed, and the drug will no longer be covered.

"He's sitting at home thinking, 'what is going to happen next?' He knows his physiology," Horn says. "You're left feeling like your hands are tied."

Editor’s note: This article was updated to include that Dr. Horn is a paid consultant for Novo Nordisk.