I had several compression fractures in 2016 and it took about 4 months for the Forteo to noticeably start working and my fractures to stop. The pain journey was intense from the repeated fracturing. I did the full 24 months of Forteo and believe it saved my life. Now, 2025 I am doing another course of Forteo (generic brand) and because I don't have fractures this time, I can tell you more specifically my noted side effects are minor. Some joint pain and lower back ache. Stiffness and initial headache, tummy upset that resolved itself in the first few months. Now on my 9th month of daily injections and mostly doing fine.. Some stiffness but I am 67, and had lost 4 1/2 inches in height with the fractures, so think that's to be expected. I am very appreciative of Forteo and the amount of research that was done before its release. I had excellent follow up in 2016 by Forteo. Nothing this time around. Seems we all have to really do our own research and advocacy these days.