Big Pharma and Coca Cola turning obese American teenagers into patients for life with obesity injection drug that has scary side effects Does America really need an obesity drug for 12-year olds that causes cancer tumors? Wegovy (semaglutide) is now the first FDA-approved weight loss drug approved for obese adolescents that is taken once a week. Wegovy lists its serious side effects as possible thyroid tumors that include cancer. Got a swelling in your neck, trouble swallowing, and shortness of breath? That’s not the obesity talking, that’s your new weight loss prescription drug catapulting what’s also known in lab-tested rodents as medullary thyroid carcinoma (MTC).