a semaglutide self-injection pen on a table alongside measuring tape

The new generation of weight loss medications has become a sensation, from the pages of medical journals to People magazine. Jimmy Kimmel and Christina Applegate quipped about Ozempic, one of the medications, at Hollywood awards shows. Oprah Winfrey, who showed off a slimmed down look on the red carpet recently, said she'd added weight loss drugs to her fitness regimen. Science magazine named this class of medication, glucagon-like peptide-1 (GLP-1s), as the 2023 Breakthrough of the Year.

GLP-1s have produced meaningful results and hold much promise. But what are the realities of these drugs for the many who want to lose weight—and for addressing the global epidemic of obesity?

Early evidence from a number of clinical trials suggest that individuals can lose approximately 20% of their weight in 12 to 18 months while on the medications. This is far greater than seen with lifestyle intervention or the previous generation of medications, which typically produce weight losses of 5-10% in six to 12 months. While the GLP-1s do not reach the weight losses seen with bariatric surgery—typically 25-35% of an individual’s weight in the first two years after surgery—the average weight loss is associated with improvement in a range of obesity-related health conditions.

The promise and challenges of anti-obesity medications

David Sarwer, senior associate dean for research and strategic partnerships and director of the College of Public Health’s Center for Obesity Research and Education, was recently quoted in GQ magazine echoing the belief that the medications are a game-changer. He also believes there are important issues to be resolved in 2024 and beyond.

“There is great enthusiasm from the clinical trials published over the past few years," he says. "However, there are real world issues that need to be addressed. We are hearing reports of supply chain issues where patients who receive a prescription for the medication cannot have them filled. As a result of this logistical issue, companies have moved into the void and are offering 'counterfeit' medications that may not be effective and could be dangerous.”

Even if the supply chain issue is resolved, there are other challenges to getting these medications to those who need them. The medications are expensive, costing approximately $1,000 per month in some cases, though they are sometimes less expensive in other countries. For many, the medications are not currently covered by insurance. “Given that obesity differentially impacts persons from underserved group, in the absence of robust insurance coverage, the medications may not be affordable to those who need them the most," he points out.

Encouragingly, Pennsylvania is one of the few states in which the state Medicaid program covers anti-obesity medications, including some of the newer GLP-1s. This coverage could greatly increase access to these promising medications for individuals with lower income. However, it is too early to know how Medicaid coverage for anti-obesity medications impacts utilization and whether there are other insurance-related barriers, such as prior authorizations, that hinder use.

Adherence to the medications also may become a relevant issue. Many people think of weight loss interventions as short-term solutions. Most of the early evidence suggest that patients regain their weight if they stop taking these medications. Gabriel Tajeu, associate professor in the Department of Health Services Administration and Policy, studies strategies to improve adherence to antihypertensive medications. Low adherence to those medications, which often are prescribed to persons with both hypertension and obesity, can limit their effectiveness.    

“Socioeconomic status, lower levels of education, and limited access to health services are factors associated with low adherence to antihypertensive medication," he notes. "Unfortunately, these social determinants of health also are common among individuals with obesity. It will be important to develop strategies to maximize adherence to GLP-1s as well.”

In fact, all three main treatment modalities for obesity—lifestyle modification, anti-obesity medications, and bariatric surgery—are underutilized by the tens of millions of people who could benefit from them.

Treatment initiation and adherence can be impacted by the conversations that patients and providers have about treatment. Leah Schumacher, assistant professor in the Department of Social and Behavior Sciences, studies patient-provider communication related to obesity treatment and authored a paper with Sarwer on this issue last year.

“We know that the conversations that patients have with their providers about obesity can be very impactful in both good and bad ways," she says. "For example, some patients may have terrific experiences with their providers, while others, unfortunately, may feel stigmatized, judged, or dismissed. For these medications to help as many people as possible, it will be important for providers to understand how these medications work and who may benefit from them, and to then actively involve patients in the treatment decision-making process in an empowering way.”

Sarwer agrees. “I’m also concerned about patients' expectations about early weight loss. If a patient expects to lose 20 pounds in the first three months of being on the medication, but only loses 15 pounds, they may be disappointed and discontinue the medication. In reality, a 15-pound loss in three months is a great start.

“All of these issues will need to be addressed if the GLP-1s are truly to become the breakthrough in obesity treatment we hope it will be, " he says.

Sarwer, Schumacher, and Tajeu have grant funding from the National Institutes of Health to support their research. Sarwer has consulting relationships with NovoNordisk and Twenty30 Health, companies which work in the area of obesity treatment delivery.