This study investigates the effectiveness of different types of over-the-counter iron supplements for patients who have undergone bariatric surgery and are experiencing iron deficiency. Bariatric surgery includes procedures like Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), which can sometimes lead to iron deficiency. The study compares various new iron formulations with ferrous sulfate to see which works best for these patients.

Participants in the study will take oral iron supplements and their progress will be monitored to see how well their iron levels improve. This involves taking different iron formulations and tracking their effectiveness. The study does not involve any invasive procedures and focuses on the oral intake of supplements.

• Who can participate: Adults who have had RYGB or SG bariatric surgery at least 6 months ago and are iron deficient can participate. Exclusions include those who are pregnant, have severe anemia, or have had parenteral iron recently, among other criteria.
• Study details: Participants will take different oral iron supplements as part of the study. Some will receive a placebo, which is an inactive substance that looks like the investigational medicine but does not contain any medicine.