Iron Supplement. Gentle to Your System. High Potency. One per Day Mason s Slow Release Iron gives you the high potency iron you need the gentleness you want. This slow release formula is shown to reduce the side effects common to iron use.* 60% fewer incidence of GI side effects compared to immediate release iron tablets. Guaranteed no added: Starch, sodium, yeast, soy, corn, wheat, gluten, egg, fragrance, artificial flavors, and preservatives. This product has been manufactured and packaged in strict conformance with industry and government standards. *This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or pr.