A drug or substance that reduces hunger and food intake, developed for the treatment of obesity. The history of this class is sobering: amphetamine-based suppressants caused addiction and heart damage, fenfluramine damaged heart valves, and several later agents were withdrawn for psychiatric or cardiovascular harm. The modern generation, led by GLP-1 receptor agonists, works through gut-brain satiety pathways with far better safety data, though they still require medical supervision and lifestyle support. Non-drug appetite suppressants include protein, fiber, and water consumed before meals, which promote fullness through normal physiology. The enduring lesson is that appetite is a deeply regulated survival system, and overriding it pharmacologically demands respect for the complexity being manipulated.