Oral iron replacement therapy is often used as a first-line modality for the treatment of iron deficiency anemia (IDA). Oral iron replacement options include tablets, capsules, and liquid formulations. Esophagitis due to iron tablet administration is a well-documented phenomenon, yet peptic ulcer disease secondary to iron tablet administration is less well-known. An 83-year-old female with a past medical history of chronic kidney disease stage V, anemia of inflammatory disease, heart failure with preserved ejection fraction, and gastroesophageal reflux disease presented to the hospital with diffuse abdominal pain and dark red emesis. She was started on ferrous sulfate supplementation two weeks ago and described progressive abdominal pain and nausea since beginning the medication. She was not taking nonsteroidal anti-inflammatories (NSAIDs), antiplatelets, or anticoagulants. Six months ago, she had an unremarkable upper endoscopy performed for new-onset gastroesophageal reflux disease. Laboratory studies revealed a hemoglobin of 7.3 mg/dL and due to a concern for rapid blood loss, she was given one unit of packed red blood cells. A non-contrast computed tomography was performed showing wall thickening of the stomach and the first two portions of the duodenum. A possible ulcer was seen in the distal posterior stomach. The patient was made NPO, and twice daily intravenous pantoprazole was started. An upper endoscopy was performed which revealed a 2.5 cm clean-based ulcer in the duodenal bulb. Biopsies showed acute inflammation and positivity for iron debris but were negative for Helicobacter pylori. Once daily pantoprazole was continued, and her ferrous sulfate tablets were discontinued. Her symptoms did not return. Ferrous sulfate may erode and ulcerate the gastric and duodenal mucosa like that of a chemical burn. Iron deposits may be seen on biopsies performed with Prussian blue staining. Brown crystalline deposits may be seen on hematoxylin and eosin staining. Iron injury may be seen in pill or capsule formulations due to a concentration effect, but this is typically not seen with solution forms. Treatment includes discontinuation of tablet or capsule formulations and substitution with liquid forms.