I took Forteo about 9-10 years ago. If I recall correctly, my doctor ordered one set of bone marker tests in the first few months to determine it was working and then a dexa at one year. Unfortunately, I wasn't as informed back then on the importance of bone markers so I did not request it on a regular basis. At the time, I was under the care of two endocrinologists who specialize in osteoporosis management and they just followed the drug manufacturer's recommendation with little thought as to personalization and optimization. Along those lines, one thing that makes me somewhat skeptical of the study cited (other than my personal experience of losing density the second year of treatment) is that it was sponsored/paid for by Ely Lily with all authors involved either employees, investors or consultants which gives rise to a slant towards recommendation of full compliance of a 2 year protocol. It does state that "a clinical trial in which patients are randomized to different durations of teriparatide treatment has not been performed"