Purpose: NABT: To compare five widely available nitrate formulations: (1) 15 of nitroglycerin (NTG) ointment, (2) 0.3 mg and (3) 0.6 mg of sublingual NTG, (4) 20 mg of isosorbide mononitrate (an oral tablet), and (5) 160 mg of glycerol trinitrate (a patch), for their efficacy on markers of bone formation and resorption and for the incidence and severity of headache they cause.