# How Weight-Loss Drugs Like Mounjaro and Wegovy Work
Mounjaro and Wegovy represent a new class of medications that target the body's appetite regulation system rather than simply speeding up metabolism. Both drugs belong to a family called GLP-1 receptor agonists, which mimic glucagon-like peptide-1, a natural hormone your body produces.
When you inject these medications, they activate receptors in your brain that control hunger and satiety signals. This makes you feel fuller faster and reduces cravings between meals. The drugs also slow gastric emptying, meaning food stays in your stomach longer, extending that feeling of fullness. Additionally, they improve how your body manages blood sugar levels, which stabilizes energy and reduces appetite spikes.
Mounjaro, made by Eli Lilly, uses tirzepatide as its active ingredient and targets two different receptor types simultaneously. Wegovy, manufactured by Novo Nordisk, contains semaglutide and focuses on GLP-1 receptors. Both come as once-weekly injections that patients self-administer.
The difference between appetite suppression and metabolism change matters. These drugs don't burn calories faster. Instead, they help you consume fewer calories by genuinely reducing hunger rather than relying on willpower alone. Studies show people using these medications lose significantly more weight than through diet and exercise alone.
In the UK, the NHS makes these drugs available to certain patients, typically those with a BMI over 30 or those with weight-related health conditions. Private prescribing remains an option for others. Cost ranges from hundreds to thousands of pounds depending on the route and duration of treatment.
Weight returns when people stop taking these medications, so they work best alongside lasting lifestyle changes. Common side effects include nausea, vomiting, and diarrhea, particularly when