Iron supplements commonly include ferrous sulfate tablets and ferrous fumarate tablets, and there is generally no optimal time to take them, but they are mostly recommended to be taken with or after meals. Iron supplements commonly include ferrous sulfate tablets and ferrous fumarate tablets, which can be used for many causes of iron deficiency anemia. There is no optimal time to take them, but these medications may cause some gastrointestinal adverse reactions such as nausea, vomiting, epigastric pain, and constipation. Therefore, it is mostly recommended to take them during or immediately after meals, which can reduce gastric irritation, but drug absorption is affected. It should also be applied with caution in patients with alcoholism, hepatitis, acute infections, intestinal inflammation, pancreatitis, etc., and in patients with gastric and duodenal ulcers, ulcerative enteritis. It should not be taken with strong tea. Allergy is prohibited. Patients should follow the doctor’s instructions to use the drug.