I reluctantly started fosomax due to the potential aide affects but conceded when my pmr morphed into gca and i had to go on high dose Prednisone. I have been on it for a year and a half and Was able to maintain my bone density after a year which my dr was very pleased given my high does of Prednisone for a year. I do have osteoporosis. I have not had any side effects so far. I've had a couple major relapses so i will continue to take it until i get off or a very low dose of Prednisone. But everyone is different but it's very important to protect your bones. There are other biphosfonate that you could look into maybe. Good luck to you