I was anemic -tired, pale, short of breath and I began taking Walgreens Ferrous Sulfate 325 mg which = 65 mg elemental Iron twice a day and it worked.

I dont really know the answers to your questions, but I know I took this a saw a vast improvement. I had more energy and my cycle improved temendously.

The doctor recomended this dosage but not the brand...still worked though, even though it was the inexpensive one...