My sister has lost about 45 pounds taking one of the new GLP-1 drugs. More importantly, she is improving her health significantly. I know several other people taking them as well.

I began to look, and if the statistics I found are anywhere close to right, I know quite a few more people who simply have not mentioned they are taking them. And so do you.

That got my attention.

I started looking into GLP-1 drugs and quickly realized that something much bigger is happening here than I had appreciated. I suspect many of you already know more about them than I did. But for the rest of us, this seems like a trend worth investigating.

What is GLP-1?

GLP-1 stands for glucagon-like peptide-1, a hormone our bodies naturally produce after we eat. Among other things, it helps regulate blood sugar, slows digestion, and sends signals to the brain that we have had enough to eat. GLP-1 and GIP, or glucose-dependent insulinotropic polypeptide, are both incretin hormones released after meals and involved in glucose control and satiety. (PubMed).

The drugs we often hear about, including Ozempic, Wegovy, Mounjaro, and Zepbound, amplify these biological signals. Semaglutide, the active ingredient in Ozempic and Wegovy, is a GLP-1 receptor agonist. Tirzepatide, sold as Mounjaro and Zepbound, goes a step further by acting on both GLP-1 and GIP. (PubMed). Now that I am paying attention, I noticed an advertisement for Zepbound on television last evening.

That is a lot of vocabulary, and I had to look up everything to paint this picture. I am still assimilating it.

GLP-1 is recognized as a satiety signal that slows gastric emptying and helps reduce food intake.The result for many people using GLP-1 drugs is dramatically reduced hunger and food intake. (PubMed).

But how well do they really work?

This is where I began to understand why these drugs are different from the endless parade of diets and weight-loss programs we have all seen over the years.

In a major clinical trial, people taking semaglutide lost an average of about 15% of their body weight over 68 weeks. In another large trial, people receiving the highest dose of tirzepatide lost an average of about 20.9% of their body weight over 72 weeks. (PubMed; SURMOUNT-1).

For perspective, for a person weighing 250 pounds, a 15% loss is about 38 pounds, and a 20.9% loss is more than 52 pounds.

These statistics are averages, not promises, and individual results may and will vary considerably. But we are talking about weight loss on a scale that simply was not typical of earlier medications.

These results strike me as fundamentally different from Atkins, Weight Watchers, and the many other approaches we have watched come and go. Those programs primarily ask us to change what and how much we eat and perhaps exercise along the way.

GLP-1 medications work differently by altering some of the biological signals affecting hunger and satiety.

GLP-1 drugs do not eliminate the importance of good nutrition and exercise. But they accomplish something that diet and exercise alone have not for many people: they change some of the biological signals that influence hunger and how much we eat. The NIDDK also emphasizes that weight-management medicines should support healthy eating and physical activity, not replace them. (NIDDK).

In other words, rather than simply asking people to resist hunger and eat less, these drugs make them feel less hungry and satisfied with less food. That has certainly been my sister’s experience. This may help explain why the weight loss seen in clinical trials has been so much greater than with earlier medications and typical lifestyle interventions. (NIDDK).

We are talking about more than just looking thinner and being healthier.

The most important thing I learned is that the medical story has moved well beyond weight loss.

The FDA has approved Wegovy to reduce the risk of cardiovascular death, heart attacks, and strokes in certain people who have cardiovascular disease and are overweight or obese. The FDA also approved Zepbound for moderate-to-severe obstructive sleep apnea in adults with obesity, and Wegovy for MASH, a serious form of fatty liver disease. (U.S. Food and Drug Administration; FDA; FDA).

So these are increasingly becoming drugs for diseases associated with obesity, not simply drugs for losing weight.

How many people are taking them?

This may have surprised me most.

A Gallup survey conducted this year found that 11% of American adults say they are currently taking GLP-1 medications for weight loss, up from only 3% in 2024. About 15% say they have used them at some point. (Gallup.com).

Another survey, conducted by KFF, looked more broadly at GLP-1 use for weight loss, diabetes, and other conditions and found that 12% of American adults were currently taking one of the drugs. This study also examined GLP-1 use by age, sex, race, affordability, and even political affiliation. We may take a closer look at the KFF study later. (KFF).

Whether 11% or 12% of adults are taking GLP-1 medications, that adds up to roughly 30 million adult Americans. And millions more have tried them in the past.

Now consider the potential population for usage. The latest CDC data based on measured heights and weights show that about 40% of U.S. adults have obesity, and about 30% of adults are classified as overweight. The point is that the potential scale of future usage is enormous. (CDC; NIDDK).

Where is the catch? There are several.

The most common side effects are gastrointestinal, including nausea, diarrhea, vomiting, and constipation. There are also less common but more serious risks, including gallbladder problems and pancreatitis, and the drugs are not right for everyone. (U.S. Food and Drug Administration). You should have seen the potential side effects shown in the Zepbound advertisement I mentioned!

Cost and insurance coverage remain significant issues. In KFF’s 2025 survey, about half of users said the drugs were difficult to afford. (KFF). The older friends I know without insurance other than Medicare have been paying about $300 per month for their weekly injections. Under a new Medicare Bridge Plan, which is set to last until December 2027 and was opened this month, some will be able to obtain their drugs for $50 per month. My sister entered this plan this month.

The Trump administration is working to make these drugs more accessible and less expensive for many Americans, and recently announced the Bridge Plan and the results of other efforts in this vein.

There is also the question of what happens when people stop using the drugs.

In one follow-up study of semaglutide users, participants regained about two-thirds of the weight they had lost within a year after stopping use of the drug. That suggests that for many people, GLP-1 treatment may be less like going on a diet and more like taking medication for high blood pressure or high cholesterol. In other words, it is not a one-time thing for a period, but a long-term treatment for a chronic condition. (PubMed).

GLP-1 drugs have been used in diabetes treatment for years, so they are not new. However, we lack decades of experience with this many people using the newer drugs at the current scale for weight management. There is still much to learn. (PubMed).

I do not come away from my brief investigation into GLP-1 drugs and their use thinking they are miracle drugs without drawbacks. They have real side effects, costs, uncertainties, and medical considerations that need to be addressed with physicians.

But I do come away thinking the GLP-1 phenomenon is quite different from any other weight-loss fad I have ever seen.

Something significant is happening.

Millions of Americans are already taking these medications. They are producing levels of weight loss that would have seemed extraordinary from a drug just a few years ago. Their known medical benefits are expanding. And the population that could potentially benefit from them is enormous.

Which leaves me with another set of questions.

What happens if these drugs continue to improve? What happens if they become easier and less expensive to take? What happens if tens of millions more people use them — and eat less, weigh less, and become healthier?

What is already changing? And what else might change in the coming years?

These are questions I want to think about.

Before closing, let’s return to the beginning of this post for a bit about one person’s experience so far.

My sister tells me she has felt hungry all her life. Now, for the first time, she feels like she has control over her eating rather than food having control over her. She is grateful for the weight she has lost, but even more grateful for what it is already doing for her health and how she feels.

There is still a great deal we do not know about GLP-1 drugs. But for her, at least, they have already provided another reason to age gratefully.

Until next time, be well, and age gratefully,

Chris

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