Receptor for relaxins. The activity of this receptor is mediated by G proteins leading to stimulation of adenylate cyclase and an increase of cAMP. Binding of the ligand may also activate a tyrosine kinase pathway that inhibits the activity of a phosphodiesterase that degrades cAMP. Interacts with C1QTNF8. Expressed in the brain, kidney, testis, placenta, uterus, ovary, adrenal, prostate, skin and heart. Not detected in spleen. Belongs to the G-protein coupled receptor 1 family.