The present invention provides novel short-chain peptides, which primarily actas parathyroid hormone (PTH/PTH-I) receptor agonist. These short-chain peptides exhibit increasedstability to proteolytic cleavage. Most of short-chainpep-tides were found to be stable in rat plasma upto 24 hours (in vitro),showed increased stability against GIT enzymes such as pepsinand acidic stomach pH and also against liver microsomes (in vitro). Due toincreased metabolic stability, other than parenteralroute of administration, some of the short-chain peptides can also bedelivered by oral routes of administration, for the treatment /prevention of hypoparathyroidism and diseases characterized by bone massreduction, such as osteoporosis, postmenopausalos-teoporosis and for stimulating bone repair. A-Z1-Z2-Z3-Z4-Z5-Z6-Z7-Z8-Z9-Z10-Z11-Z12-Z13-Z14-Z15-B
