AMNA NAWAZ: 2024 was a big year for weight loss drugs like Ozempic and Wegovy.

More patients are relying on them to manage their weight, treat diabetes or prevent heart attacks and strokes.

And while they are highly effective, they also come with some concerns.

William Brangham has more on the rising demand for these drugs, which are part of a class of medications known as GLP-1.

WILLIAM BRANGHAM: About one in eight U.S. adults now say they have taken a GLP-1.

But amid all the excitement about their efficacy, some experts also say it's important to keep in mind some of the drugs' limits, their costs, and to better understand where they belong in the nation's long fight against obesity.

For a check-in on where this all stands, we are joined now by Dr. Jody Dushay.

She's an assistant professor of medicine at Harvard Medical School and a clinical endocrinologist who specializes in medical weight management Dr. Dushay, so nice to have you on the program.

You prescribe these drugs to some of your patients.

From your perspective, what do they do?

How effective are they, especially at helping people lose weight?

DR. JODY DUSHAY, Division of Nutrition, Harvard Medical School: Well first, I want to say thank you very much for having me.

It's a pleasure to be on the show.

And, also, I just want to mention that I don't have any conflicts of interest.

So, in terms of how these medications work and how effective they are, a lot of times, what I will hear is patients using the same words to describe how they work.

So people will tell me that they have reduced cravings, that they think about food less.

A lot -- there's been use of this term food noise.

So people will tell me that they have a lot less food noise, so they are thinking about food a lot less, whereas, maybe, before, you wake up in the morning and you're thinking about what you're going to have for breakfast.

While you're having breakfast, you're already thinking about what you're going to eat next after that.

And that is really quieting down for people, as well as a easier time with portions, so eating -- still eating food that is enjoyable to them, but eating less of it and feeling satisfied.

Those are -- those are the main things that I hear from people who take these medications to lose weight -- to help with weight loss.

WILLIAM BRANGHAM: Couple of questions about the downsides of these things.

Do they work for everyone, and what are the side effects that patients experience?

DR. JODY DUSHAY: They work for many people, but they don't work for everyone.

There are nonresponders.

There is a significant minority of nonresponders.

In my clinical practice, that is probably about 10 percent; 10 to 12 percent of people don't respond to these medications.

We don't know why.

There aren't at the moment any clear predictors of response, but, certainly, there are nonresponders.

And in terms of side effects, they are very, very common.

Most commonly, people have reflux, nausea, a little less commonly kind of vomiting, constipation or diarrhea, either which can be severe, and also some less common side effects, such as fatigue.

But, overall, I do tell people that side effects are very common, and they should expect to experience some side effects.

WILLIAM BRANGHAM: As you know, these drugs are extremely expensive in the U.S. And while they are demonstrating real effectiveness, that creates challenges with affordability and access.

How do you see that playing out in your own practice?

DR. JODY DUSHAY: Insurance coverage is a major problem.

So, at the moment, Medicare does not cover these medications for weight loss.

The exception is semaglutide.

It's covered for secondary prevention of cardiovascular disease.

So that is the only way that you can Wegovy covered by Medicare.

And in terms of private insurances, either there is no coverage or you have to go through hurdles, meaning you have to try other medications and either not tolerate them or not have weight loss with them.

Or, sometimes, it's just a full stop with the private insurance.

They just will not cover medications for weight loss.

So access does remain a major problem, largely due to lack of insurance coverage and the very high cost of paying out of pocket.

WILLIAM BRANGHAM: Given their efficacy that you have seen, would you like to see insurance coverage broadened, including Medicare?

DR. JODY DUSHAY: Yes, definitely, especially for higher body weights and higher body mass indices, or for people who may have lower body mass indices.

However, they have significant metabolic comorbidities, such as high cholesterol, high blood pressure, pre diabetes.

If they have cardiovascular disease, as I said, they might be covered.

But, certainly, people who are in the high risk category due to comorbidities or to due to very, very high body weight, I would very much like to see expanded coverage.

WILLIAM BRANGHAM: What do you make of the argument -- I'm sure you have heard this -- that, given their efficacy of helping people lose weight, that that in some way forces us to take our eye off the ball off of proper nutrition and exercise in this fight over obesity?

DR. JODY DUSHAY: These medications are meant to be prescribed only in combination with a program that is paying attention to nutrition and to physical activity.

So this is in the context of what someone is able to afford and physically do.

However, there always should be a component of nutrition counseling and also physical activity counseling as well.

So these medications are never meant to be used as a substitute for that, and always in combination for best health and also for optimizing how much weight loss you're going to get with these medications.

So you're going to get additional benefit if you pay attention to lifestyle.

They really are not meant at all to be a replacement for that.

WILLIAM BRANGHAM: All right, Dr. Jody Dushay of Harvard Medical School, thank you so much for being here.

DR. JODY DUSHAY: Thanks so much.