Tirzepatide works by mimicking the GLP-1 and GIP hormones that are naturally secreted by the intestine after a meal, which prompts insulin secretion. It also reduces appetite by slowing down the time it takes the stomach to empty and interacting with areas in the brain harboring GLP-1 receptors to signal satiety. Most people who follow a healthy diet and exercise routine begin reporting some weight loss within a month to two months of starting the medication. Weight loss can occur at lower doses before reaching the maximum dose, but significant weight loss is typically achieved at sustained higher doses.