The Ozempic and Mounjaro Effect: Weight Loss, Rebound and the Future of Obesity Treatment
A weekly injection, minimal effort, and dramatic weight loss. Drugs like Ozempic and Mounjaro have rapidly transformed the global conversation around obesity treatment. Originally developed for Type 2 diabetes, these medications are now among the most talked-about tools in the wellness industry after users reported striking weight loss. From Hollywood celebrities to India’s urban wellness circles, the injections are widely discussed across social media, celebrity interviews, and fitness communities. But alongside the excitement, doctors are warning about a growing concern often referred to as the Ozempic rebound – the tendency for weight to return once the medication is stopped.
How the Drugs Operate
Both medications belong to a class known as GLP-1 receptor agonists, which mimic the hormone glucagon-like peptide-1. This hormone plays a key role in regulating appetite and blood sugar 1.
When the drugs are taken regularly, they slow digestion, reduce hunger signals, and make the brain feel full sooner. For many patients, this leads to smaller meals, fewer cravings, and gradual weight loss. But the effect depends on the drug remaining active in the body. Once injections stop, appetite regulation gradually returns to its natural state.
Why the Body Regains Weight
Doctors say the rebound is largely biological rather than behavioral. “When the medication stops, appetite hormones return to their previous levels,” explains Dr. Navoday Gilla, Senior Consultant in Internal Medicine and Diabetology at KIMS Hospitals 1. “That means hunger increases again. Without dietary discipline and physical activity, weight regain becomes incredibly common.”
Rapid weight loss can also trigger physiological responses. Metabolism may slow slightly as the body adjusts to reduced energy intake, and cravings can intensify once appetite suppression disappears. Research published in The Lancet has also suggested that stopping GLP-1 therapy may lead not only to weight regain but also to a reversal of improvements in blood sugar control and cardiovascular risk factors. In effect, the body often tries to return to its previous set point.
A Bridge, Not a Shortcut
Doctors emphasize that these medications were never intended to replace lifestyle changes. Dr. G V Rao, surgical gastroenterologist and laparoscopic surgeon and director, Asian Institute of Gastroenterology, says the drugs can serve as an important starting point for patients struggling with severe obesity 1.
“It is easy to advise running or jogging,” he says. “But many obese patients simply cannot do that initially given that their knees or joints cannot support it.” For such patients, the medication can help reduce enough weight to make physical activity possible.
“In that sense, it works as bridge therapy,” he explains. “It allows patients to start exercising and modifying their diet. But if lifestyle changes are not introduced during treatment, the results may not last. If people stop the drug without adopting long-term lifestyle changes, weight gain becomes very likely,” Rao says.
Long-Term Treatment or Lifestyle Reset?
Some specialists believe GLP-1 medications may eventually be used as long-term therapy for certain patients. Dr. Kesava Reddy Mannur, clinical director of metabolic and bariatric surgery, Continental Hospitals, says obesity behaves more like a chronic metabolic disease than a temporary condition.
“That means some patients may require ongoing medical therapy to maintain weight loss,” he explains. “When treatment is stopped, the body’s biological mechanisms often push weight back toward its earlier levels.” He adds that medications should be seen as one part of a broader treatment strategy.
“These drugs can help patients lose significant weight initially. But maintaining that weight loss depends on whether patients adopt lasting lifestyle changes such as healthier eating patterns and regular physical activity.”
Preventing the Rebound
Doctors say preventing weight regain requires building sustainable habits while the medication is still working. Dr. Suma Sandhyala, Consultant Plastic Surgeon at Apollo Hospitals, says the mechanism is straightforward. “These drugs suppress appetite. When that effect fades, hunger gradually returns.”
But she cautions that relying solely on medication can create unrealistic expectations. “Protein- and fibre-rich diets can improve satiety and reduce cravings. Strength training and regular exercise help maintain muscle mass and support metabolism. Gradually tapering medication under medical supervision may also help the body adapt more smoothly. Adequate sleep, stress management, and nutritional counseling can also improve long-term outcomes,” she adds.
India is poised to develop into a key, low-cost supplier of these drugs as patents expire, potentially driving down costs by as much as 90 percent 1. Mounjaro, a tirzepatide injection drug, has already become India’s highest-selling drug, overtaking antibiotics, eight months after its approval 3. Demand for appetite-suppressing drugs such as Mounjaro, Wegovy and Ozempic has surged since they were introduced into the Indian market this year 3.
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