In peptic ulcer disease, antacids present a therapeutic effect by neutralizing gastric acid and reducing acid delivery to the duodenum. Furthermore, they reduce the activity of pepsin and have the capacity to bind bile acids. Despite the opinion of most clinicians, the effect of antacids relieving pain in patients with peptic ulcer has not been definitely demonstrated. Furthermore, antacids do not seem to improve the healing rate of gastric ulcer. Earlier studies showed that antacids could hasten the healing of duodenal ulcer when administered at a very high dose. However, recent papers demonstrate that this therapeutic effect is also achieved with a dose with very low neutralizing capacity. Severe side effects are rare, although they can occur in high-risk patients. However, minor problems, such as changes in bowel habits, are more frequent.