Thanks so much for sharing your questions and concerns with us. Being diagnosed with osteopenia at such a young age can be very quite a challenge, but it is far better to know and be able to do something about it than to wait for a fracture. It's a very good thing you took your family history a height loss (one of the few visible symptoms of a mainly invisible condition) seriously.

Your endocrinologist is right, many osteoporosis medicines are designed for, tested in and approved only for postmenopausal women. However, you should be aware that some medications, in certain situations, are sometimes prescribed to younger individuals and even children with osteoporosis. Different physicians have various perspectives and philosophies regarding the possible benefits and risks of going this route. Bisphosphonates (such as Fosamax) have sometimes been prescribed in younger patients, and sometimes doctors even recommend Forteo for those with very compromised bone mass.

However, since you are still of childbearing age, it is very important to remember that osteoporosis medications would generally not be suitable for anyone who is pregnant or nursing, or could potentially become pregnant during treatment. (Forteo, for example, specifically mentions this on its web site.) And many doctors believe they should not be prescribed in premenopausal women until there is more research available (and specific FDA approval.)

In any case, it is good you are already thinking about how best to take care of your bones, and I wish you the best in the future. Do keep us posted!