Will You Keep Losing Weight if You Switch From a GLP-1 Shot to a Pill?

People using GLP-1 injections to treat obesity may at some point consider changing to a GLP-1 pill, which can be more affordable and possibly easier to manage. But there’s been limited research into whether the switch could derail someone’s weight loss progress.

The study, which was presented at the annual meeting of the European Association for the Study of Diabetes, found that patients who switched from weekly injectable GLP-1 medications to the daily Wegovy pill lost 4.1 percent of their body weight within the first three months after the change.

While the study was conducted by the maker of the Wegovy pill, Novo Nordisk, and the telehealth company Ro (which prescribes the Wegovy pill), “the findings are very believable,” says Richard Siegel, MD, a codirector of the Diabetes and Lipid Center at Tufts Medical Center and an endocrinologist at Tufts Medicine Weight & Wellness Center–Stoneham in Massachusetts, who was not involved with the new research.

Doctors say the latest data suggests people may be able to see weight loss success with either form of GLP-1, injectable or oral.

The Study Makes a Case for the Wegovy Pill

For this investigation, researchers analyzed health records and patient-reported data from Ro. The data came from 194 people who switched to the Wegovy pill after using the injectable form of semaglutide (Wegovy, Ozempic) or tirzepatide (Mounjaro, Zepbound).

Participants were followed for three months after making the change to the pill. On average, patients with obesity lost 8.8 pounds (lb), or 4.1 percent of their body weight. The number of patients who were classified as clinically obese dropped from about 87 percent to 65.5 percent during this time period.

The majority of patients — 87 percent — reported that they took the oral medication daily, and 75 percent said they were satisfied with their treatment.

Doctors Aren’t Shocked by the Findings

The Wegovy pill has been popular since its launch, but the public largely seems to view injectable forms of the medication as better, says Jamie Alan, PharmD, PhD, an associate professor of pharmacology and toxicology at Michigan State University in East Lansing.

“The oral form does work; it’s just a little bit less effective than the injectable,” says Mir Ali, MD, the medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, California.

Dr. Siegel agrees, but he adds that switching GLP-1s from an injectable to an oral does not guarantee weight loss. “Ongoing weight loss will depend on persistent lifestyle changes and probably the dose of the oral semaglutide,” he says.

Siegel also points out that people eventually plateau on GLP-1 medications for weight management, whatever the form. “With semaglutide, the plateau is usually 10 to 15 percent [weight loss], if diet and activity are optimal,” he says.

During a maintenance phase, he adds, a GLP-1 medication will continue to “keep appetite down and satiety up.”

Study Has Limitations

The study’s results haven’t yet been peer-reviewed or published in a medical journal, which means the findings can’t be considered conclusive.

Gitanjali Srivastava, MD, an obesity medicine physician and a professor at Vanderbilt Health in Nashville, Tennessee, calls the results “encouraging,” with a few caveats. “This should be read as early, hypothesis-generating data,” she says. “This is real-world evidence from a single telehealth platform, sponsored by the manufacturer, and it only looked at patients who stayed on the pill for three months.”

That study design naturally selects people who were doing well on the pill and tolerating it, Dr. Srivastava says. Plus, she says, “There’s no comparison group, and three months is short in obesity care, where we think in years,” she says.

But doctors say there is value in the latest data. “More data is good, and now people have more evidence that switching from the injection to the pill will support weight loss,” Dr. Alan says.

Oral GLP-1s May Be a Better Fit for Certain Groups, According to Doctors

A GLP-1 pill may be helpful for people who can remember to take medication daily, Siegel says. Beyond that, “it should be good for either initial weight reduction or maintenance,” he says.

It can also provide another option for people who are nervous about taking a shot, have a history of injection site reactions, or who have potential issues with being able to refrigerate their medication, Alan says.

Affordability may be a factor, too. “If the cost is lower for oral medication, it may allow more access,” Siegel says.

Overall, “The oral form is a viable option for many people,” Dr. Ali says.