The most common side effects are flatulence (in 5% of people taking the drug), diarrhea (4%), constipation (4%), stool color change (4%), nausea (3%), vomiting (3%), and abdominal discomfort, bloating and pain (1%).

[5][10] Ferric maltol may cause serious side effects including increased risk of inflammatory bowel disease flare and iron overload in the body.

Food reduces its uptake from the gut, as do calcium and magnesium salts and tetracycline antibiotics.

[9] Ferric maltol acts as a source of iron, which is essential for oxygen transport in the blood and other processes in the human body.

Iron is bound to transferrin and reaches its highest concentrations in the blood plasma one to three hours after ingestion.