I have been taking these Ferrous Gluconate iron supplements for quite some time but yesterday I accidentally bought Ferrous Fumarate instead. How different are the two?

Ferrous fumarate is organic iron made from a plant source and can be used by the body more effectively and does not tend to cause constipation.

Ferrous gluconate is inorganic iron made from a rock source and that's why it tends to cause constipation in some folks. Also, the molecules are bound together very loosely and the iron can easily break free to bind with and destroy vitamin E.

Hope this is helpful and feel free to contact me with questions.