Iron drops like Tonoferon can cause temporary staining on a baby's teeth or gums. To prevent this, administer the drops using a dropper directed toward the inner cheek so the supplement bypasses the teeth and goes straight to the back of the throat. Immediately after feeding, gently wipe down the baby's gums and teeth with a clean muslin cloth to remove any residue. This simple habit is highly effective at preventing long-term staining.