I started on Forteo in 2014 and finished up in 2016. Prior to starting, I had 2 or 3 thoracic fractures and my bone density was very low. I was nervous about Forteo but it was either continue to loose more density and experience more fractures or try the medication. The only significant side effect I recall was knee pain and possibly some back pain. When I finished up on Forteo, the knee pain went away. Of course the increased bone density starts to subside after you finish up so my Dr. then prescribed Prolia which I still take. I have not had any thoracic fractures since. However, I took a serious tumble about eight years ago which resulted in a fractured femur. Not sure any medication would have prevented that fracture. Before starting Forteo, I did a lot of research and finally decided, with my low bone density and my thoracic fractures (which are so painful and debilitating), I needed to go forward with the Forteo and Prolia and I do not regret it.