An N-terminal fragment of PTH; PTH receptor agonist; binds to the PTH1 receptor (IC50 = 2 nM) and increases cAMP accumulation (IC50 = 0.22 pM) in HEK293 cells expressing human PTH1; stimulates cAMP accumulation in Saos-2 human osteoblast-like cells (IC50 = 0.38 nM); stimulates bone resorption from neonatal mouse calvariae in vitro; increases bone mass in an ovariectomized adult rat model of postmenopausal osteoporosis at 40 μg/kg per day; increases proteoglycan content and inhibits articular cartilage degeneration in knee joints in a mouse model of injury-induced osteoarthritis at 40 μg/kg per day immediately following injury