The present invention relates to a polypeptide, or pharmaceutically acceptable salt thereof, comprising the formula PTH(1-X)/PTHrP(Y-36). Further, the present invention refers to a polypeptide which binds the PTH receptor and has a high affinity for the R 0 form of the PTH receptor and to a polypeptide having affinity for PTH RG and a low affinity for PTH R 0 . Moreover, the present invention includes to a pharmaceutical composition comprising such polypeptide. The present invention further relates to a polypeptide or a pharmaceutical composition of the present invention for use in a method for treating a disease or condition. Moreover, the present invention refers to a nucleic acid comprising a sequence encoding a polypeptide of the present invention, a vector comprising said nucleic acid, a cell comprising said vector and a method of making a polypeptide of the present invention. Finally, the present invention further relates to a method for determining whether a candidate compound is a long-acting agonist of a G protein coupled receptor (GPCR).
