osteoporosis
"I was prescribed Prolia by my endocrinologist 4 years ago for osteopenia.  My experience with it is 90% positive; it has completely reversed my bone loss, and my bones are continuing to improve (I'm in my mid 60s and have experienced declining bone density since menopause in 2004).  No side effects, except for possible lower back pain which my specialist did say may happen.  Not sure whether Prolia caused this, as it only happened once; I spend a lot of time working out and may have hurt my back then.  Great drug!  Fantastic for bone loss; highly recommended if you don't experience side effects.  Beats nasty bisphosphanates hands down!  Downside is the cost; this drug isn't covered by Medicare (in Australia) unless you have had a fracture."