Iron supplements can cause dark green/black stools. This is expected and harmless.
Nursing Tips / Iron supplements and stool April 12, 2021 Updated: March 11, 2025 Cathy Parkes, RN BSN PHN CWCN Share Share Link Close share Copy link Iron supplements can cause dark green/black stools. This is expected and harmless. Back to blog Leave a comment Name * Email * Comment * Please note, comments need to be approved before they are published.