Iron supplements are used as a common remedy to treat iron deficiency for years. Despite widespread research of iron on primary teeth discoloration, their esthetic side effect on permanent teeth remains underexplored. The objective of this study was to assess the effect of different viscosity and pH of two commonly used iron supplements on enamel discoloration of extracted permanent teeth. Sixty extracted single-rooted permanent teeth were divided into three groups: Ferosoft (pH-5.25, viscosity