What doctors wish patients knew about anti-obesity medication

In the battle against obesity, physicians play a crucial role in guiding patients towards a healthier and more sustainable lifestyle. While healthy eating and physical activity remain fundamental pillars in weight management, there are instances when additional support becomes necessary.

Enter anti-obesity medications—Food and Drug Administration-approved medications to help people achieve and sustain a healthier weight. But the world of anti-obesity medications is complex, and these new and emerging tools are often misunderstood.

The AMA’s What Doctors Wish Patients Knew™ series provides physicians with a platform to share what they want patients to understand about today’s health care headlines.

For this installment, two obesity medicine physicians took time to discuss what patients need to know about anti-obesity medications. These AMA members are:

• Carolynn Francavilla Brown, MD, a family physician in private practice at Green Mountain Partners for Health in the Denver area. She is chair-elect of the AMA Private Practice Physicians Section Governing Council and an obesity specialist.
• Ethan Lazarus, MD, a family and obesity medicine physician in Greenwood Village, Colorado, and represents the Obesity Medicine Association (OMA)in the AMA House of Delegates. He is also the past president of OMA.

“When someone starts to lose weight, their metabolic rate adjusts,” Dr. Francavilla Brown said. “But that metabolic rate—how many calories you burn in a day—actually starts to go down as you’re losing weight. And that’s where people start to see less results.”

“Then your body does a second adjustment, which is called appetite regulation, where it actually will make you hungrier and it will make you less full when you’re losing weight because it really wants you to keep that weight on,” she said. “So, your metabolism goes down and your hunger goes up and your fullness goes down."

“Those are really challenges, and the reason why most people are not going to have long-term success without medication or surgery,” Dr. Francavilla Brown said. “People should not feel discouraged if they feel like they have tried all the right things and they’ve done all the right things. They probably have. It is not a lack of willpower; it is biology.” 

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“The newer medications are the injectable medications and that's really what's creating quite a stir in the news and on TikTok and all that kind of stuff,” Dr. Lazarus said. “The injectable weight-loss medications are basically repurposed diabetes medications.”

“We’ve been using this GLP-1 class for type 2 diabetes for a long time. This is a hormone that your small intestine makes that signals that it’s time to stop eating,” he explained. “I like to think about that as a satisfaction hormone. So, when your gut releases GLP-1, it’s in a response to eating and you feel satisfied. It’s a nice feeling.”

“The difference between the injectable GLP-1 medications and your gut is when your gut makes GLP-1, you break it down really quickly—two or three minutes. So, as soon as it stops making it, you don’t feel satisfied anymore,” Dr. Lazarus said. “When you do a GLP-1 injection, the newer ones last a week. So, 24 hours a day, seven days a week, you feel like you just ate. It’s not that you’re stimulated and you have all this energy and don’t want to eat. It’s very calming.”

“Two years ago, Wegovy [semaglutide] was approved and it’s part of a group of medications that have been out for a while, so we know quite a bit about them. But they were only used for diabetes previously,” Dr. Francavilla Brown said. “Wegovy is a weekly shot so that has been really convenient for most of my patients and it has an average of about a 15% to 16% weight loss for people. So, it was the most dramatic weight loss medication we had so far.”

There is a “newer medication, Mounjaro [tirzepatide], which has been approved for type 2 diabetes and we expect it to be approved soon for chronic weight management. Studies have shown 20% to 22% weight loss,” Dr. Lazarus said. He noted there are also “some other medications in development hitting as high as 24% to 25% weight loss.”

“I usually divide anti-obesity medications into two categories, which would be the oral medications and the injectable medications,” Dr. Lazarus said. “The older, oral medications generally work as mild appetite-suppressing medications—just decreasing the patient’s desire to eat.”

“Most people describe that they’re able to snack a lot less so that they’re able to have more of that normal pattern of eating three meals a day. And a lot of people will describe that they’re able to eat smaller portions,” Dr. Francavilla Brown said. “They just don’t think about food as much. Food becomes more like fuel on that medication.”

“When combined with a healthy eating and physical activity plan, people can expect to lose around 10% of their body weight on the oral medications,” Dr. Lazarus said.

“The older medications are mild stimulants, so they can raise heart rate or blood pressure, cause insomnia and shouldn’t be used in patients with advanced heart disease or hard-to-control high blood pressure,” Dr. Lazarus said. “One of the oral medications called Contrave has an antidepressant and an anti-addiction medication in it—bupropion and naltrexone. That one shouldn’t be used if you are on narcotic pain medication.”

Contrave “can cause headaches, insomnia, nausea,” he said, noting “the injectable medications primarily cause gastrointestinal side effects. So, after a shot of Wegovy, people can feel pretty tired for the weekend. People can get nausea, heartburn, diarrhea, constipation, but most people end up tolerating it over time.

“And the way they do that is they start at a really low dose and every month you go to the next higher dose. This helps minimize side effects,” Dr. Lazarus said.

When it comes to Ozempic and Wegovy, these are two brand names for the same medication. The main difference is Ozempic is for diabetes “and Wegovy is the weight-loss version, but they are the same chemical, which is semaglutide,” Dr. Francavilla Brown said. “So, they’re the same peptide—semaglutide—and they’re made by the same company, Novo Nordisk.”

The difference is in the dosing.

“We use higher doses of those injections for weight loss than we use for diabetes,” she said.

All anti-obesity medications prescribed are Food and Drug Administration (FDA) “labeled and, of course, recommended to do so along with nutrition change,” Dr. Francavilla Brown said. “So, some sort of nutrition plan and increase in physical activity. We really see that the medications work better long-term when people increase their physical activity level.”

While taking an anti-obesity medication, “we need to look at the things in life that are barriers to weight loss. We’ve got to talk about excess stress, inadequate sleep, abnormal or highly processed foods, family stressors, travel, business engagements,” Dr. Lazarus said, emphasizing “there should be a lifestyle intervention around healthy eating, physical activity, stress reduction, improving sleep and dealing with barriers to weight loss.”

“Obesity is a chronic illness and it should be treated chronically over the long haul. So, unfortunately, many times people take the medication for the short term,” Dr. Lazarus said. “What we’ve seen is if a person loses weight on an anti-obesity medication and stops it, most of the clinical studies have shown that they’ll regain at least two-thirds of the lost weight within 12 months. And within a couple years they usually are back to where they started, so they should be taken chronically.”

“Most of our meds are like that. We compare it to depression, high blood pressure or diabetes medications. Any chronic condition we have in health care, if a medicine is what solves that problem, then you have to stay on a medicine,” Dr. Francavilla said. “That doesn’t mean you can’t switch medicines. You might be able to switch which medication you’re on, but if you need a medicine to treat the disease of obesity, the vast majority of people are going to continue to need some sort of medication for their weight.”

When taking anti-obesity medication, “we want to see patients losing at least 5% of their body weight during the first three months of treatment. And most patients by six months of treatment, we would love to see 10% or more body weight loss,” Dr. Lazarus said. “We would call 5% or more a clinical success, but we want to see 10% or more. So, 5% is the lowest bar we would say it’s doing something.”

For example, “if a 200-pound individual lost 20 pounds, that’s starting to be medically very meaningful. And what patients want is a lot more than that,” he said. “A lot of times patients want to lose 30% or 40% of their body weight and that’s not typically what’s going to happen. For a high responder on these medications, sometimes we’ll see as high as 15% to 20% body weight loss.”

“If a person loses 10% or more on an oral medication, they’re doing great. If they lose 15% or more on Wegovy, they’re doing great,” Dr. Lazarus said. “And then, Mounjaro is going to adjust our expectations because we’re going to be looking for 20% or more. So, that allows us to tailor the treatment to the patient depending on the burden of disease of obesity and how many problems it is causing, and what percentage of weight loss will be needed to improve those problems.”

“These anti-obesity medications are all approved for people who have the disease of obesity, which is currently defined largely based on BMI [body mass index]. So, these are not for cosmetic weight loss,” Dr. Francavilla Brown said. “If you want to lose five or 10 pounds for a wedding or a beach vacation, these medications all do have risks and it probably wouldn’t be worth taking this medication for something like that.”

“People who have eating disorders—such as binge eating—often do really well on these medications,” she said. “But those patients really need special support from someone who’s familiar with eating disorders where they can focus more on treating that binge eating as opposed to focusing on how much weight they’re losing.”

Additionally, “most of these medications are now approved for age 12 and up. That is a newer thing that’s happened over the last few years,” she said, noting that “12 and up is for all our newer brand-name medications.

“Our older phentermine—because it’s such an old medication, there’s no new FDA approvals coming out for it,” Dr. Francavilla Brown added. Both Qsymia and the two injectables—Saxenda (liraglutide) and Wegovy—are approved for patients 12 or older.

“One of the things we’re doing with obesity that’s a problem is—it’s a progressive disease. People are gaining weight every year and we wait until the weight is incredibly high before we offer any treatment,” Dr. Lazarus said. “We really want to get people on treatment sooner. Once the BMI is getting over 30, it’s a really good time to be thinking about starting on a treatment for teens or adults.”

“It’s the same as diabetes. You don’t want to wait until the person with diabetes goes blind before you start treating the diabetes. You want to treat even earlier. You want to prevent diabetes,” he said, emphasizing that one of the AMA’s primary strategic objectives is “identifying prediabetes and preventing it from progression to type 2 diabetes. And what’s the best way to do that? Treat their weight.”

“Losing 6% of your body weight lowers your risk of progressing to type 2 diabetes by two out of three,” Dr. Lazarus said, noting that has been shown by the National Diabetes Prevention Program lifestyle-change program.

“We’re finding somewhere in the range of 20% to 30% of health insurers are covering the anti-obesity medications. And then 70% or so of Americans don't have coverage,” Dr. Lazarus said, noting that “most of the coverage is determined state by state. So, some states have anti-obesity medication as part of their essential health benefit package, but most of us don’t.

“In that scenario, it’s dependent on the employer. What we see is really good coverage among large employers. … But a lot of the smaller companies, like a private practice physician like me or an attorney practice don’t have coverage,” he added. “So, when there’s coverage, the medications are very cost effective. When there’s not coverage, they’re not.”

But “there has been a bill in Congress for about a decade called TROA—the Treat and Reduce Obesity Act—to try to get Medicare to cover these medications,” Dr. Francavilla Brown said, noting “Medicare actually has specific policy against allowing the coverage of weight-loss medications, so that’s been a big advocacy challenge and insurance companies are not required to cover these medications either.

“Most state Medicaid programs currently do not cover these and most private insurance plans don’t cover them unless the employer has opted into coverage,” she added. “So, that’s a very big challenge and why sometimes our older generic medications are the best fit for people due to cost.”

“Which medication makes sense for a patient is going to depend partly on coverage of the medication, cost of the medication, side effects of the medication, other medications and other medical problems,” Dr. Francavilla Brown said.

Consulting an obesity medicine physician “who is an expert in these medications is often the way to go.”