thank you for your query.
both are similar compounds of iron with different densities and chemical ratio.Ferrous gluconate
(organic) is much better absorbed than ferrous sulphate
(inorganic) as organic supplements are much better absorbed than inorganic supplements.its just that inorganic supplements need to be taken in greater amounts than organic supplements.
Some people tolerate the gastrointestinal side effects of ferrous gluconate better than ferrous sulfate
. Therapeutically, they are the same and you can use the ferrous sulfate instead of ferrous gluconate.
it just depends on which drug your stomach tolerates better.
wishing you good health