PPARβ/δ, which regulates lipid metabolism and energy homeostasis, also has a role in bone homeostasis, report Scholtysek and co-workers. In mice deficient in PPARβ/δ, Wnt signalling activity and serum concentrations of osteoprotegerin were reduced, whereas osteoclast numbers and rates of osteopenia were increased. By contrast, in a mouse model of postmenopausal osteoporosis in which PPARβ/δ was pharmacologically activated, bone turnover was rebalanced and bone density was restored to normal. The researchers suggest that PPARβ/δ is a promising target for the treatment of osteoporosis.