The popularity of pricey GLP-1 drugs has hit the budgets of users — and just about everyone else.

In the U.S., about 12 percent of adults say they’re already on them. And worldwide, more than 25 percent of adults could benefit from the weight-loss treatment, according to new research from Mass General Brigham.

The Trump administration in November announced new deals to lower the cost of the notoriously pricey drugs to a $50 monthly copay for people who rely on Medicare for health insurance. But costs vary widely — causing some states to end coverage or restrict who qualifies for them under Medicaid plans.

And the newly launched TrumpRX platform offers some GLP-1 discounts aimed at those who lack insurance or would pay more under their coverage.

The drugs’ popularity and price are already driving up the cost of health insurance across the board, says Luca Maini, assistant professor of health care policy at Harvard Medical School. 

“If you look at the change in your health insurance premium this year over last year, about 30 percent of that is GLP-1s,” Maini said. 

The Gazette spoke with Maini about how public and private insurers are adjusting to the surging use of GLP-1s.

This conversation has been edited for length and clarity. 

Why have these drugs been so expensive? 

They’re expensive in part because they’re effective, and patients value what they offer. But they’re also patent-protected, so generic drug manufacturers can’t produce these compounds for another few years. The companies that make these products are effectively monopolists. 

Now, there is some competition, because there are a handful of these molecules that can be used for weight loss. And the price has come down quite a bit, even in the last few years. A recently approved Wegovy pill will cost $150 a month for patients without insurance. But we can expect the cost to remain relatively high, at least while the patents are in effect. 

Why is there so much variety in what a patient ends up paying for these drugs? 

It depends on the type of coverage you have. Medicaid has very low out-of-pocket costs and covers virtually all drugs, but only a few states cover anti-obesity medications. Even patients in one of those states that do face substantial access restrictions. A Medicaid patient would need access to a physician who can write a prescription, and to go through administrative hurdles like prior authorization. Medicare Part D, which is the part that covers prescription drugs, does not cover drugs that treat obesity — though that may be changing under the Trump administration’s recent deals with manufacturers.

Employer-sponsored plans tend to be more generous when it comes to coverage, but they also require more cost-sharing and, again, administrative hurdles like prior authorization.

And lastly, out-of-pocket payers can access these drugs through the direct-to-consumer, telehealth services that are popping up online, which offer prescriptions at around $100 or $200 per month these days. 

How unusual is it for so many patients to be eligible for a new class of drugs but face such a high cost? 

It’s pretty much unprecedented, especially when you’re talking about one in four adults being eligible for these drugs under the widest standards. The only comparison I can think of is statins [commonly prescribed to lower cholesterol].

A similar share of adults is eligible for those drugs, but much cheaper generics are available — and when they first came out, they weren’t nearly as widely prescribed. 

On the flip side, I’m reminded of the treatments for hepatitis C that arrived on the market a little more than 10 years ago. Of course, fewer people need treatment for hepatitis C, but the products were much more expensive when they first came out, so the burden on the healthcare system was comparable.

What happened in that situation was that the drugs were heavily rationed — in a sense that’s the natural solution, and the same thing is happening with GLP-1s. It’s part of why the fully out-of-pocket, direct-to-consumer channel is so popular: because a lot of patients can’t get the drug reimbursed through their insurance. 

How disruptive have these drugs been for insurance companies? 

Well, it’s certainly disruptive, but the solution, from the insurers’ perspectives, is clear: Raise the cost of coverage, or at least the cost of insurance plans that cover these drugs.

One thing that’s different about these drugs is that at least when it comes to treatment for obesity, patients can basically predict perfectly whether they’ll need them, and that means the insurer can do the same thing. So it’s actually fairly easy for them to figure out what kind of budget impact this will have on their bottom lines, and how much they need to raise premiums to make up the difference.

That’s already happening. If you look at the change in your health insurance premium this year over last year, about 30 percent of that is GLP-1s. 

Should we expect those insurance premiums to keep going up or has the impact of GLP-1s mostly been factored in at this point? 

I would say the biggest adjustment has been factored in, though some uncertainty remains.

The biggest uncertainty is how long patients continue to take these drugs. They’re meant for long-term use. But evidence shows that as of now, GLP-1s have pretty unpleasant side effects, and a lot of patients stop taking them. So the financial impact may not be as steep as it would appear.

The other factor is whether or not these drugs end up having benefits that reduce costs in other areas. Obesity is a comorbidity that tends to worsen other outcomes, whether that’s cardiovascular health, risk of falls, things like that.

So it remains to be seen how much money is saved if some of those outcomes are improved. 

How is this shaking out in other countries?

The main difference is that in most other countries the fraction of people who would benefit from these drugs is smaller. Still, the majority of European countries, for example, have imposed very strict utilization controls, generally limiting use to patients with high body mass index.

Is there any relief on the horizon? 

Yes. In the short term, the Centers for Medicare and Medicaid Services, the federal agency that administers Medicare and partners with state governments to manage Medicaid, is testing what would happen if Medicare Part D covered GLP-1s for obesity — to get a sense for how much it would cost, and what those positive externalities might be. 

And finally, even if it turns out these drugs have to be taken for life — and most people do — in about next five years or so, these patents will start to expire, and we’ll have generic manufacturers making their own GLP-1s.

At that point, they’ll be very, very cheap. So even in the worst-case scenario, from a spending perspective, we can think of this moment as a very expensive blip.