Hey, I'm Flor Lichtenen, and you're listening to Science Friday.

Today in the show, those popular weight loss drugs and the science of how they work.

The drugs work primarily. I'm not saying this is the only way they work. They work essentially

through their adverse effects. Over the past couple years,

a class of drugs has dominated the headlines. I'm talking about GLP-1 medications like Wagovi,

Zempec, Zepbound. You might be taking one. You might know somebody who is. In a new book, former FDA commissioner, Dr. David Kessler, aims to go beyond the headlines

to take a close look at the science on metabolism, weight loss, and how these new blockbuster

drugs actually work.

Dr. Kessler has a personal relationship with the subject.

He's taken a GLP1 medication himself. His book is called Diet, Drugs, and Dopamine, and Dr. Kessler has a personal relationship with the subject. He's taken a GLP1 medication himself.

His book is called Diet, Drugs, and Dopamine, the new science of achieving a healthy weight.

David, welcome back to Science Friday.

Thanks for having me.

You wrote an op-ed on these GLP-1 drugs for the New York Times, and there were 740 comments as of the time that I looked at it.

Why do you think this medication is a lightning rod? Well, I think there are an opportunity to

reverse for me this epidemic of chronic disease. They are not a panacea. They are one tool in a toolbox.

The one thing about these drugs that I think everybody can agree on is that they work through biology.

And that means this struggle that many of us have experienced throughout our lives, this struggle with weight,

is not willpower. That's what these drugs show. But all of a sudden, we have something

that we've never had before. We have a very powerful, highly effective drug that does something that we've not been able to achieve on our own.

You know, one thing that really struck me in your book was this section you had about why the weight always seems to come back.

And you talk about how when you lose weight, your body actually starts to burn fewer

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