Iron infusions typically start to show improvement in symptoms within a few days to a week. However, it generally takes about 4 to 6 weeks for the full results, such as stabilized iron levels and correction of anemia, to be evident. Some people may notice changes in energy, fatigue, and overall well- being as early as within one week, with more substantial improvement over several weeks. Doctors usually recommend follow-up blood tests around 4 to 6 weeks after the infusion to assess iron levels and response to treatment. The infusion itself usually takes about 15 to 30 minutes to administer, and patients are typically observed for about 30 minutes afterward for any reactions.