GLP-1s Grow Up: What the Latest Research Means for People Taking Them

GLP-1 weight loss drugs used to be a niche market, but now they are part of everyday American life. One in eight adults (12%) currently takes one, and nearly one in five has tried one, with current use roughly doubling since early 2024.

These medications, sold under names like Ozempic and Wegovy (semaglutide) and Mounjaro and Zepbound (tirzepatide), copy a natural gut hormone that helps control blood sugar and reduce appetite. They were first developed for those with type 2 diabetes and are now predominantly used for weight loss.

As use has grown, so has research into potential uses beyond weight loss. Analysts project that the combined weight-loss and diabetes drug market could approach $100 billion a year by the end of the decade.

“These drugs have quickly moved mainstream, and those who are taking these drugs, or individuals who are interested in taking these drugs, need clear, practical guidance on both benefits and potential downsides,” says Whitney English, Registered Dietitian at Plant-Based Juniors.

A new generation of options

Weight-loss drugs first came onto the market as weekly injections, which, while effective, also created a distinct disadvantage for those who didn’t want to visit a health care provider weekly or were uncomfortable with self-injecting.

Now, drugmakers are rolling out more choices: Eli Lilly’s oral orforglipron (sold as Foundayo) and a Wegovy pill are currently on the market, with longer-acting shots projected to roll out soon. Pfizer is testing a once-monthly injection, which would be more convenient than weekly dosing and therefore able to reach more individuals. Newer combination drugs, such as Lilly’s triple-agonist retatrutide, which is not currently on the market, have produced dramatic weight loss in late-stage trials.

For consumers, this means more options and possibly simpler routines. English adds, “I’m especially hopeful for what the increase of options means for affordability and allowing those whose insurance doesn’t cover the costs to be able to reasonably self-pay.”

Beyond the scale

Research on GLP-1 drugs in 2026 goes beyond just weight loss. A Penn Medicine analysis of more than 110,000 women found that those taking GLP-1s were about 30 percent less likely to develop breast cancer, though the researchers stressed the study was observational and cannot prove the drugs were the cause.

A separate systematic review presented at the Endocrine Society’s 2026 meeting suggested the medications may raise testosterone and improve sperm quality in men with obesity, while again cautioning that the evidence is still preliminary.

Observational data means just that; researchers studied people who were already taking the drugs, rather than randomly choosing who got them with controls as would be done in a trial. These kinds of studies are interesting and can help with potential associations, but cannot prove cause and effect.

The protein scramble

For individuals currently taking these drugs, the rapid weight loss isn’t all fat. In the STEP 1 trial behind semaglutide’s obesity approval, up to 40% of the weight people lost was lean body mass, compared with roughly 25% that is typically seen with caloric restriction.

The habits around these drugs can further impact this, as individuals taking GLP-1s tend to move less after starting them; one study showed moderate-to-vigorous activity dropped from 28 to 22 minutes a day.

Because the drugs blunt appetite, many users eat less of all macronutrients, protein included. During active weight loss, many experts recommend increasing protein intake to 1.2 g/kg body weight, above the usual 0.8-1.0 g/kg, along with strength training to help preserve muscle.

Demand for more protein has been strong enough to move markets. Rising interest, partly from GLP-1 users and partly from social media, has led to limited whey supplies and pushed prices higher.

“Powders and shakes are convenient, but aren’t my first choice when it comes to quality protein,” says English. “Instead, I recommend focusing on protein that also contains fiber and antioxidants, especially as constipation is a common complaint from users of these medications.” Fiber helps keep things moving and can be found in lentils, beans, tofu, and whole grains.

The social and financial burdens

Public attitudes have not yet caught up with the science. Rice University research found people often judged GLP-1 users more harshly than those who lost weight through diet and exercise,  and even more harshly than those who had not lost weight at all, a stigma tied to the perception that the drugs are an “easy way out.”

A 2026 National Restaurant Association survey found that nearly half of GLP-1 users dine out less often than before, while about one in four go more often. Many change what they order, choosing smaller portions, more protein, and more vegetables.

Cost can add additional pressure. About half of adults in the May 2024 KFF Health Tracking Poll described the medications as difficult to afford, and insurance coverage for obesity-only use remains uneven. However, cheaper oral versions may eventually narrow this gap. 

English summarizes, “Using them well means preserving muscle mass and weighing costs. For now, the most accurate framing may also be the simplest: promising, and still being figured out.”