(D-Phe(sup 2)-phe(sup 5)-D-phe(sup 6))-LHRH (D-Phe(sup 2)-phe(sup 5)-D-phe(sup 6))-luteinizing hormone-releasing hormone Luteinizing hormone-releasing hormone, (D-phe(sup 2)-phe(sup 5)-D-phe(sup 6))- OK6666000