Anti-ulcer agents are pharmacological compounds used to prevent and treat ulcers of the gastrointestinal tract, particularly those affecting the stomach and duodenum. These agents act through various mechanisms, including suppression of gastric acid secretion, enhancement of mucosal defense, and promotion of healing of the gastric lining. Major classes of anti-ulcer drugs include proton pump inhibitors (PPIs), H₂-receptor antagonists, antacids, and mucosal protective agents. In recent years, increasing attention has been given to herbal and natural products for anti-ulcer therapy due to their potential efficacy and favorable safety profiles. A thorough understanding of the mechanisms of action, therapeutic indications, and adverse effects of anti-ulcer agents is essential for the effective management of peptic ulcer disease and for improving patient outcomes.