Double strength iron - 36 mg iron is an essential mineral that plays central roles in energy production, immune system function, and neurological health. ( iron is an essential component of hemoglobin, a molecule that transports oxygen to the cells of the body, and myoglobin, which binds oxygen used in muscle tissues. Now uses ferrochel® iron bisglycinate, which has clinically demonstrated superior absorption and is well tolerated because it is gentle and non-constipating. Ferrochel® iron bisglycinate gentle & non-constipating 90 veg capsules. Now double strength iron - 36 mg 90 capsules (90 servings)