Fosamax was a positive medication for me. I took it steadily for two years and had a slight increase in bone mass. I read an article from a university study that said collagen type 2 would also work so I stopped taking Fosamax and used collagen and again had an increase. I'm opting for the collagen though my doctor has suggested Prolia. I'm 69 years old and pretty active. I lift weights and bike ride as often as I can. Btw I had no side effects from Fosamax.