I developed a large kidney stone while on Tymlos. It took 9 months to get it diagnosed, because where I was feeling pain wasn't where the doctors thought that pain from a kidney stone should be. No one ever checked the level of calcium in my urine. Finally had to go to ER because the pain was so bad. I had a large kidney stone inside my kidney which was too large to ever pass on its own. I had surgery to place a urinary stent between my kidney and my bladder to keep my ureter from getting blocked. Miserable experience. Had to wait about 4 weeks with the stent in place to get surgery to break apart and remove the stone. Had a stent for a few weeks after that. My Tymlos went in the garbage after that - I will take my chances. I had told my doctor before starting Tymlos that both my brother and my Dad had kidney stones. I had never had them before taking the Tymlos.