Hi marian, welcome and thanks for your question.  Forteo is given as a daily injection for 2 years.  I took it and did really well increasing my t-scores from osteoporosis to mild osteopenia.  You need to follow Forteo with another drug to maintain any gains you might make, so that's something to think about.   Forteo is a man made form of parathyroid horomone very similar to what your parathyroid gland makes on it's own.  The parathyroid is seperate from your thyroid, and controls calcium and phosphate production in the body.   Here's an article, from the Cleveland Clinic, on Forteo that explains how it works, what's in it, and the possible side effects.  If you've ever had radiation to the bone or bone cancer you can't take it.   Good luck and if you have any more questions just ask.