The Yuzpe method of pre-implantation/emergency 'contraception'
The Yuzpe method of postcoital birth control was developed in the late 1970s. This treatment consists of two doses of an artificial 'estrogen' plus artificial 'progesterone' tablet. The first dose is taken within 72 hours of 'unprotected' intercourse, and another dose 12 hours later. Each dose contains 100ug of ethinyl estradiol (the artificial estrogen) and 0.5mg of levonorgestrel (the artificial progesterone). (1) Unprotected intercourse can include an act of rape, or a failed barrier method i.e., condom, spermicide, or a voluntary act of intercourse with the woman not wishing to present with a detected pregnancy. Note, to avoid unnecessary longhand, I will henceforth refer to levonorgestrel as a progestin, its proper pharmaceutical classification, rather than the secular term 'artificial progesterone'.
(1) Trussell J, Rodriguez G, Ellertson C. op.cit,, p.147