PT-141 is a peptide used in the treatment of erectile dysfunction and libido. PT-141 is an isomer of the already known melanotan-2 peptide. PT-141 works for both men and women. Even a single administration of PT-141 causes a significant increase in libido in both sexes. The form of administration is friendly to most users, as PT-141 can be used subcutaneously or intranasally (spray). A peptide praised by many practitioners.