The invention relates to a method for increasing the toughness and/or stiffness of bone in a man, in particular for reducing the likelihood and/or severity of bone fracture by administering parathyroid hormone hPTH(1-34) by subcutaneous injection at less than 1 µg/kg/day. The method can be employed to increase toughness or stiffness of bone at a site of a potential or actual trauma, such as the hip or spine of a person at risk of or suffering osteoporosis. The method of the invention can reduce the incidence of vertebral fracture, reduce the incidence of multiple vertebral fractures, reduce the severity of vertebral fracture, and/or reduce the incidence of non-vertebral fracture.
