Ferrochel™ Iron Bisglycinate Gentle & Non-Constipating* 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™ and the Albion Gold Medallion designs are trademarks of Albion Laboratories Inc. NOW® Double Strength Iron has twice the Iron (36 mg per capsule) as in our regular strength product (18 mg per capsule). Natural color variations may occur in this product.