One of the reasons why medications known as GLP-1 agonists or dual agonists have been so effective for weight loss is that they counteract the body’s natural responses to increase hunger and promote weight gain. “These drugs mimic naturally occurring gut hormones that control hunger and give them back to individuals in fairly high amounts,” Kushner says. As a result, someone taking one of these medications doesn’t feel hungry, so they’re less likely to overeat.
It’s also been noted that these kinds of drugs dial back what is known as “food noise”: cravings, thoughts, and desires for food that can feel constant and intrusive. “Hunger is mediated by lots of things. Along with being habitual, it can be spiritual or emotional,” Youdim says. “When my patients take these drugs, they tell me they’re able to make sustained changes more effectively without all this noise that gets in the way.”
Each drug uses a different active ingredient to accomplish these tasks. Wegovy and Ozempic contain semaglutide, and Mounjaro and Zepbound have tirzepatide. Another drug, Saxenda, contains liraglutide. The medications all work on receptors for GLP-1, mimicking the effects of that hormone when it comes to appetite and making you feel more full. In biochemistry, anything that causes a response in this way is called an agonist. Drugs that contain tirzepatide are known as dual agonists because they affect receptors for both GLP-1 and GIP.
In addition to helping you feel fuller, GLP-1 agonists slow the rate at which food empties from your stomach, which delays the usual hormonal signals to your brain indicating that you need to eat, says Daniel J. Drucker, MD, a senior scientist at Lunenfeld Tanenbaum Research Institute at Mount Sinai Hospital in Toronto. This twofold effect means you aren’t as hungry in general and may be able to go longer between meals without getting hungry.
Of course, these medications aren’t for everybody. The U.S. Food and Drug Administration (FDA) approved these medications for people with a body mass index (BMI) of 30 or above, which is classified as obesity, or anyone with a BMI of at least 27 and at least one weight-related health issue like diabetes, high blood pressure, or cardiovascular disease. “These drugs are designed to treat medical issues, not cosmetic ones,” Youdim says.
While these new medications have shown enormous potential for treating obesity, experts stress that they are not a cure. They are most effective when used in conjunction with healthy lifestyle habits such as regular exercise, stress management, and a healthy diet, and they have to be taken long term, usually for life.
Everyday Health’s Weight Loss Reframed Survey queried 3,144 Americans nationwide ages 18 and older who had tried losing weight in the previous six months. The study was fielded between July 10 and August 18, 2023, across demographic groups, genders, and health conditions. Survey recruitment took place via an online portal, in app, and via email. The margin of error for the sample size of 3,144 is +/-1.7 percent at a 95 percent confidence level.
