Side Effects of Medicines: There are a number of medicines and nutritional supplements, which when taken for some time, give a metallic taste in the mouth. Some of them are iron supplements, prenatal vitamins, certain antibiotics, hypertension medication, etc. The blood taste inside the mouth will be gone once you stop taking such medicines. Similarly, patients who have undergone surgery get a blood like taste in mouth soon after the procedure. Here, it is actually the effect of the anesthesia, which was used before the surgery.