L-Norgestrel: It is used as a female contraceptive which is defined as the progestin or synthetic form, naturally occurring in the female sex hormones known as progesterone. If the progesterone level in the body falls resulting in the menstrual period without occurring pregnancy, then it helps to trick the body process into thinking which clearly defines that ovulation has already occurred. It also helps in maintaining the high levels of the synthetic progesterone and thereby prevents the release of eggs from the ovules. This is the action and the mechanism of this drug as stated (Eugene 125-136).Diethylestilbestrol: It is a kind of drug which is used for preventing the miscarriages and the premature births in the late 1940s and 1970s. The treatment with the usage of this drug increases the risk regarding the psychological mechanisms. It also seems to be resulting in disturbed epithelial differentiation and also results in the disturbed uterine cervix. The action of this drug also signifies the disturbing development of the lymphoid system as well as the hypothalamic-pituitary gland control system. These are the mechanism and the effects that can be observed with the usage of this drug.
Ethinyl estradiol: This drug is specially used for the purpose of delaying ovulation. The important mechanism of action helps in explaining the results and thereby the ECP effectiveness can be used during the first half of the menstrual cycle. Additional possible mechanisms that are included for this drug represents the appropriate functioning of corpus luteum and the thickening of the cervical muscles which results in trapping of sperms. This mechanism and the action are represented in this following drug (Katzung 550-585). Mifepristone can be used as a postcoital contraceptive as the drug has fewer or no side-effects and can influence the development and transportation of fertilized egg. Researchers indicate that a lot of women have a delay in menstruation, but that is caused by the inhibitory factor of Mifepristone on follicular development and ovulation. The drug should not taken by those patients who are allergic or taking anticoagulants. The drug can cause dizziness and should not be used if the pregnancy is outside the womb.