PCT No. PCT/SE97/01968 Sec. 371 Date Aug. 2, 1999 Sec. 102(e) Date Aug. 2, 1999 PCT Filed Nov. 21, 1997 PCT Pub. No. WO98/23636 PCT Pub. Date Jun. 4, 1998Heptapeptide analogues or pharmaceutically acceptable salts thereof consist of a hexapeptide moiety S and a C-terminal beta -aminoalcohol residue Z bound to the moiety S by an amide bond, wherein the beta -aminoalcohol Z is -NR-CH(Q)-CH2OH, Q is (CH2)n-NH-A is H or -C(=NH)NH2, and R is CH3 or C2H5, and the moiety S wherein H is a D-aromatic alpha -aminoacid and Y is an aliphatic alpha -aminoacid and have oxytocin antagonist activity. Also disclosed is: a method of their synthesis; pharmaceutical compositions containing these analogues; the synthesis of such compositions; a method of control of uterine contractions.