Pharmacy Focus: GLP-1 Medications and Pharmacists' Role in Counseling Patients

In this episode of Pharmacy Times®: Pharmacy Focus, Donna Ryan, MD, discusses the evolution and growing significance of glucagon-like peptide-1 (GLP-1) medications in managing obesity and diabetes. Ryan highlights ongoing research exploring additional therapeutic uses, including treatment for obstructive sleep apnea, heart failure, kidney disease, and even neuroinflammation-related conditions like Parkinson disease (PD) and Alzheimer disease (AD). Ryan emphasizes the importance of using GLP-1s responsibly for medical reasons rather than cosmetic purposes, discussing potential side effects, dietary considerations, and the need for continued lifestyle modifications to maximize health benefits.

Luke Halpern, assistant editor, Pharmacy Times: Hello everyone, and welcome to another episode of the Pharmacy Times: Pharmacy Focus podcast. Today, I'm here with Donna Ryan to discuss GLP-1 medications and pharmacist’s utilization of them, and how they can help patients manage their conditions with GLP-1s. Before we get started, Donna, do you want to give a brief introduction for yourself and discuss some of your titles, positions, past positions, expertise, things like that?

About the Guest

Image Credit: © 2025 The President and Fellows of Harvard College | https://ghdcenter.hms.harvard.edu/RyanDonna

Donna Ryan, MD, is professor emerita from the Pennington Biomedical Research Center in Baton Rouge, Louisiana, where she conducted clinical research on obesity for decades. She is also the former president of the World Obesity Federation.

Donna Ryan, MD: Well first of all, Luke, thanks for having me here today. I am Dr. Donna Ryan, and I am professor emerita from the Pennington Biomedical Research Center in Baton Rouge, Louisiana. That's part of LSU, and I did clinical research on obesity there for about 25 to 30 years. My work was really in lifestyle interventions like the Diabetes Prevention Program and the Look AHEAD program. I helped develop the Dietary Approaches to Stop Hypertension (DASH) diet, things like that. I was always interested in medications, and I did clinical research in every medication that came along. I retired from that about 12 years ago, and since then, I've been consulting with companies that are trying to develop drugs in this space. I also do a lot of pro bono work. I was the president of the World Obesity Federation, and things like that. Yeah, that's me.

Halpern: Perfect Donna, that was all beautiful. Thank you for that, for detailing your work. I figured the best way to start this conversation is just to ask you what the current landscape of all these medications that are coming out, because there's always, I feel like, a new one getting approved. There are new data, new positive study data that comes out, and these GLP-1s are also now being indicated for some cardiovascular conditions. So, I just wanted to ask you for a semi-brief overview of the current landscape of these medications.

Ryan: Thank you, Luke. You know, everybody thinks the GLP-1 medications are brand new and ultra exciting. Well, they are ultra exciting. But let me tell you: we've had GLP-1 medications around for 20 years. In fact, the first one was approved for diabetes in 2005; that was exenatide (Byetta; Amylin Pharmaceuticals, Eli Lilly). The first one was approved for obesity in 2014; that was liraglutide (Victoza, Saxenda; Novo Nordisk). So, these are medications we've known for a long time. But native GLP-1, the hormone in our bodies, has effects on appetite, and it also has effects on controlling blood glucose. When your blood glucose level is high, it promotes the secretion of insulin and lowers it. The drugs have really been developed in 2 main areas: for diabetes and for obesity. But look: nobody got interested in this until about 2022, when semaglutide (Ozempic, Wegovy; Novo Nordisk) came out. Semaglutide had been around a few years for diabetes, as Ozempic, and it was approved as Wegovy for obesity. The data in people who don't have diabetes show that the weight loss was around 15% to 17%, much higher than we had gotten in prior obesity medications. This is an average weight loss of 15 to 17%. Then, tirzepatide (Zepbound, Mounjaro; Eli Lilly) came out. This is both a GLP-1 and gastric inhibitory polypeptide (GIP) receptor agonist. So, it's hitting the receptors for 2 of those gut hormones. What's important about that one is that it was associated with weight loss on average of 22.5%. This double-digit weight loss really got the public interested, but it's the doctors, I think, that really became interested in 2023 when the SELECT trial came out. It showed that this medication could prevent the second heart attack, stroke, or sudden death in people who had established cardiovascular disease. That's called a secondary prevention trial, and we had never seen anything like that before with our medications for obesity, so it really was quite a big deal. It's a combination of both the amount of weight loss that patients appreciate and the effect on disease modification, the prevention of cardiovascular disease, that really is has everyone so excited.

Right now, the drugs that are available that produce a lot of weight loss for people with obesity are Wegovy—that's semaglutide—and Zepbound—that is tirzepatide. For diabetes, the same molecules are out there as Ozempic and Mounjaro. A little confusing, but believe me, just 2 molecules, good for both diabetes and for weight management. So that's what we have available. There are still the other older GLP-1 medications. They don't produce as much weight loss and they don't produce as much glycemic control, so people are less interested in them, but they're still good medications.

Halpern: Yeah, that's a fantastic overview, because I honestly didn't know until you said that that the GLP-1s had been around that long, especially the first one being approved in 2005 I think you said, so they've been around a while. And that's a great overview.

Ryan: But really, Luke, they weren't appreciated, because the amount of weight loss that we got with liraglutide—that was marketed as Saxenda—that was only about 5% more than placebo. So, on average, with a really good lifestyle intervention, we could get 8, 9, 10% weight loss. It didn't really capture the public's imagination.

Halpern: Definitely, yeah. I mean, those improvements in weight loss…it was almost guaranteed it was going to capture the public like that. In terms of future updates on the GLP-1 landscape, are there any new o0r expected study data or approved indications on the horizon or in development?

Ryan: First of all, let's go over some recent discoveries. You know, I think the disease modifying discoveries are the ones that have really captured people's attention. So tirzepatide has a label indication now for obstructive sleep apnea—it really has a huge impact. It reduces the apnea hypopnea events that occur in people who have obesity-related obstructive sleep apnea. So that's big news. But we're also seeing clinical trial data come out that these medications are showing efficacy in heart failure (HF), HF with preserved ejection fraction especially, and in prevention of progression of kidney disease. Then there are lots of clinical trials underway, we don't have data yet, but clinical trials underway looking at if these drugs may have potential for neuroinflammation. So, things like Parkinson disease (PD) or Alzheimer disease (AD) or dementia; that would be very exciting. There's even an interest in these drugs as potential uses for smoking cessation, for addiction disorders. There are lots of things that we don't know about yet, but that are garnering a lot of attention.

I guess everyone is also really excited about the future of this class. What we're doing is we are adding agents to that GLP-1 backbone. It's not really a structural backbone. It's just the idea that we have so many positive attributes with GLP-1, well, if we add this compound to it, we could get even greater efficacy. There are 2 big studies that are out there that everyone is very interested in, and that is the combination of semaglutide with a long-acting amylin; that is called CagriSema. We're expecting the phase 3 results to come out on that any day—very excited about that. And then the other, there's what's called a single molecule triple agonist. You know, tirzepatide was GLP-1 and GIP. Well, this molecule has three: GLP-1, GIP, and glucagon. It's called a triple agonist, and it's also in phase 3. We want to see those results, because the phase 2 data make us expect that it's going to produce average weight loss in the high 20s. Those would be very powerful medications. We want to see what's going to happen there.

Halpern: Definitely. That all sounds extremely exciting, especially the possibility of AD or PD treatment; that could be a game-changer.

Ryan: Luke, the other thing that's really interesting is there are lots of other drugs, smaller companies are bringing forward drugs, and they're looking at trying to have oral medications, small molecule oral medications. That would be wonderful. They would be so much easier to produce. They. Would be easier to store. They wouldn't have to be stored on ice. They're given orally, not by injection.

Halpern: Easier to administer, too.

Ryan: Yeah, that'd be good. Wouldn't that be great? Also, to have longer acting drugs. Right now, we give these medicines by injection once a week, but in the future, maybe once every two weeks, even once a month. Wow, that would be good. So, lots of interesting spins that are coming out, and those are phase 2 and earlier drugs.

Halpern: Definitely. Yeah, that was a great overview. You mentioned so many different indications that are approved now or in the process of being evaluated. There's so many different patient groups that are affected by these new indications. What are some factors that patients should be considering when deciding whether to begin using a GLP-1 medication?

Ryan: Well, first of all, I think everybody needs to sit back and take a deep breath. These are not magic pills. They're serious medications, and so you don't really want to take them for cosmetic purposes. Any cosmetic procedure that, we require a lot, a lot, a lot of safety. How can you justify taking someone who's perfectly healthy and exposing them to health risks just because they want to look skinnier? No, no, no. These medications are not for cosmetic use. That's number one. If you do have a health risk or even health complications of overweight and obesity, these drugs are a serious consideration. But again, safety is the number 1 issue, and so we never prescribe these drugs in people who have a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2, which is a rare genetic disease that predisposes one to this type of cancer. Fortunately, medullary thyroid cancer is rare, but patients should not take these drugs who have this. Sometimes, patients can be allergic to these drugs. They are, after all, peptides—they're proteins. So, you can become allergic. They should wait until we have some small molecules around before trying this. That's also, fortunately, very rare. Otherwise, we have a pretty good idea of what the safety profile of these drugs are, because the class has been around for 20 years.

I would say the most important thing to know, for patients to know, about these drugs is that the chief side effect is going to be nausea and vomiting, and the best way to manage that is to try to prevent it. Number 1, on the day you take your shot, and for the few days after that, you should be very careful about what you eat. You need to put less food on your plate—eat only about a half of what you're used to eating—and change the food on that plate. You want to eat foods that aren't very dense and greasy foods. You want to eat foods that are lighter and that have less fat in them. Also, be sure to drink enough water, because sometimes when people don't eat, they're not getting in enough water. Those sorts of things can help prevent the nausea and vomiting. If the nausea and vomiting is severe, call your doctor. It is possible to get dehydrated because of severe nausea and vomiting. Fortunately, that's pretty rare; but still, if it's happening to you, it's not rare. You want to call your doctor, because you don't want to get dehydrated, because that can trigger kidney failure. Yeah. We don't want extreme dehydration, so call your doctor and go get hydrated up in the emergency room or whatever. I think those are the chief things that patients need to worry about.

The way these drugs work is through appetite. They change your relationship with food. You're not interested in the foods that you used to be interested in. You don't have the hunger, and you're also going to get full sooner. Don't just eat because it's on your plate. Listen to your body and stop eating. But also, you need to get in enough calories to make it safe. Sometimes, in some people, the effects of even low doses are very profound, with total absence of appetite. You must take in at least 1000 calories a day. Listen to me: you must consume at least 1000 calories a day. If you don't, you're going to get in trouble. You know, back in the old days, we would do these starvation diets. People would be on 500 calories a day, even less, and they're dangerous, because if you're not getting enough high-quality protein, you run the risk of heart arrhythmias or a sudden death. So, you cannot stop eating. You must consume at least 1000 calories a day. If you have to, go to a high protein shake, like Boost or one of the other supplements, but be sure to get in enough calories. You're going to lose plenty of weight on 1000 calories a day. Start low, start with the lowest dose, and escalate slowly. That's mostly to avoid those side effects. Don't lose too much weight. All the drugs have different doses that are available, and your doctor is going to help you find the lowest, most effective dose for you. You don't have to push that dose up if you don't need to. So those are the chief things that patients need to know around safety.

Halpern: Yeah, that was fantastic. That was extensive, and it honestly reached into some of my later questions. I appreciate that, and it's important, because I feel like nutritional guidelines are under-mentioned as an important part of your GLP-1 management experience, and you kind of touched on it.

Ryan: Luke, that's so interesting, because when we do the studies, we have to put everybody on a diet and give them lifestyle recommendations to lose weight. That is because some patients are on placebo, and if you're not helping them with their diet and lifestyle, they're leaving the study, and we want those placebo patients in there to see what would happen to make the study valid. It's very important that we do lifestyle intervention with this, and it's mostly around keeping that placebo group engaged. It's amazing, there are always people in the placebo group who lose a lot of weight.

Halpern: That is fantastic.

Ryan: Yeah! There are also some people in the intervention group, who are receiving the live medication, that don't lose much weight at all. This happens across all our medications. We don't fully understand it. With more powerful medications, fewer people are in that category; but there are still a few patients who are only going to lose 5%, but that still could be a very good thing.

Halpern: I was also going to ask, what are some lifestyle changes they should be making to their routine, not only to prevent adverse events, but also to help maximize the benefits of their GLP-1 medications for the short term and long term?

Ryan: You know, Luke, I'm so glad you asked that question, because these medications are a window of opportunity to a healthier lifestyle. You will get benefits of weight loss itself, but if you can change your diet to a higher quality of diet, and if you can change your lifestyle to include more physical activity, you will get health benefits from that. Yeah. So, we want to move to a healthier diet, a higher quality diet. We know the Mediterranean diet has health benefits. We know that from a randomized clinical trial, a gold standard clinical trial. We know that fitness is a big driver of longevity and better health. This is a window of opportunity. Don't just use these drugs to eat less; use them to have a higher quality diet and a healthier, happier lifestyle.

Halpern: Yeah, no, that was a great. The long-term impacts, I think, are especially important when it comes to the GLP-1s. When you were talking about the nutritional guidelines, again, I wanted to ask, even after patients are on these GLP-1s, after they finish their treatment with GLP-1s, should they be sustaining these dietary changes and nutritional changes for the long-term future?

Ryan: You know, Luke, we don't really know how to stop these medicines. That's the truth. What I can tell you is that if you continue the medicine, your weight loss will be maintained. The improvement in your blood glucose, in your A1c will be maintained. Whatever benefits you're getting in cardiovascular risk reduction will be maintained. Your improvements in sleep apnea will be maintained. So, staying on the medication will sustain your weight loss and sustain your health benefits. But, we do not know how to stop these drugs and sustain those benefits. Right now, our current recommendation is that patients stay on them. Sometimes patients will stop because they were taking them to achieve a certain amount of weight loss. Once people lose weight, they feel great and they think, “Oh, I got this covered now, I'm not going back to my old pattern of lifestyle.” But it's very difficult to maintain lost weight. It's virtually impossible. There are studies underway where we're looking at different strategies to try to reduce the dose, spread out the dose, maybe even stop the dose. But those studies haven't been completed, so I can't really give any advice about stopping them. It's something that we really need to be we need to be aware of. If you do stop, if you start to gain weight, for heaven's sake, don't wait till you regained all your weight; go back to your doctor and get started again.

There's one thing that I'd like to discuss, and that is how difficult it is for people to afford these drugs. It's very difficult. Sometimes, patients will go to what's called “compounding medications” that they get online or in other places. I cannot recommend this. I do not know for sure what is in those compounded medications. The compounding pharmacies are using drug lots that come from China that are not scrutinized in the way that they are when the FDA has given their approval for a product, that product is specially monitored. When we have the brand name products that are produced and sold here in the United States, we know what those are. I don't know what these compounded molecules are, and I can't endorse them, so I advise patients to stay away from that. The field is getting better, and we're going to solve this cost problem.

Halpern: Yeah, I feel like the risk with the compounded GLP-1s is major. In that vein, I feel like pharmacists, they should be able to play a role in advising patients. What role can they play in advising patients regarding compounded versions of these GLP-1s, and the proper dosing and administration of these medications as well?

Ryan: Well, you know, the medications that are marketed come with a pin. They're very simple. You don't have to use a needle to draw anything up. The pin, it's minuscule. You just put the pin against your skin and hold it there, press the button, and magically, the dose enters your body. Sometimes people do not even feel it, and you hold it there for at least 15 seconds, and then you take your pen away from the body and dispose of it. The drugs that are out on the market, both Wegovy and Zepbound, they come with an easy-to-use and administer formulation. The one thing people need to be aware of, is don't get the wrong dose to start with. You want to start with .25 milligrams for Wegovy, and you want to start with 2.5 milligrams for tirzepatide. Sometimes there will be an error made, and the patient's given the wrong dose. By all means, check your dose. But that's pretty much it. They really are totally easy to use. The compounding drugs, I do not advise. Now, those have to be drawn up in a syringe. If you are getting some crazy product online that's in a pin, it may not even be the right molecule. So be careful about that. Don't do that.

Halpern: Yes, everyone listen to Donna, do not do that. It's important. I feel like we covered a lot about this landscape of these medications. Is there anything else that you wanted to add that our audience of patients and pharmacists might find useful?

Ryan: I’d like to add one thing. I think everybody is interested in losing weight and looking their best and feeling their best, and there's nothing wrong with that. That's a good thing. But there are health benefits of behaviors that patients need to be aware of. There are health benefits of a healthy diet. There are health benefits of being physically active. We need to incorporate those in our efforts to lose weight, to feel better, and feel better about ourselves and function better. So that's my number 1 thing. These new GLP-1 medications are truly a medical advance because of the effect on our health, I frankly, don't care what your body size is. I don't care if you wear a size 20 or a size 2. What I care about is your health. The thing about these medications is that they improve health for many of the chronic diseases that we're treating. For diabetes, for pre-diabetes, for hypertension, for cardiovascular diseases, for people have problems with their lipids, for sleep apnea, for knee osteoarthritis. These medications are powerful, wonderful, health-promoting medications, and we need to treat them seriously. These are not just a medication to take because you want to get in a special dress for some event.

Halpern: Absolutely, absolutely, yeah. I mean, I think that's a perfect way to end it. Thank you, Donna, for taking this time out of your day.

Ryan: My great pleasure.

Halpern: I appreciate you discussing important parts of this newly evolving field, with weight management and diabetes and a ton of other indications, as we've discussed today. Thank you everybody for listening to this episode of Pharmacy Times: Pharmacy Focus and stay tuned for the next episode. Thank you. Thank you again, Donna.

You can listen to this episode on Apple Podcasts and Spotify.