The reproductive process is a complex physiological process including sperm and egg formation and maturation, ovulation, fertilization, implantation and embryonic development and many other steps. Blocking any of the above steps can achieve the purpose of contraception and termination of pregnancy.

The male drugs for birth control; there are few such kinds of drugs. In our country, only gossypol has been subject to mature study. Gossypol is a yellow phenolic substance extracted from the roots, stems and seeds of cotton. Administration of this drug can reduce the number of sperm, even to zero sperm with the prolonged treatment time. With the trials of more than 4000 healthy men, the effective rate is 99% or more.

Contraceptive drugs of female; According to the difference action steps, it can be divided into:
(1) contraceptive drugs inhibition of ovulation; this is a major category of female contraceptive drugs, consisting of different types of estrogen and progesterone in different doses.There are short-acting oral contraceptives. Commonly used compounds include norethisterone tablets, compound megestrol acetate tablets and long-term injection contraceptives such as compound hydroxyprogesterone caproate. Adverse reactions of these drugs include the emergence of early pregnancy response, uterine irregular bleeding, amenorrhea, decreased breast milk, coagulation hyperthyroidism and so on. It is not applicable to women of acute and chronic liver disease, diabetes and uterine fibroids.
(2) Anti-implantation contraceptives. Such drugs can interfere with the normal development of the endometrium so that it is not conducive to pregnancy implantation. China mostly applies large doses of norethisterone or megestrol acetate. The advantage of this class of drugs is not subject to restrictions on the application of the menstrual cycle.
(3) Contraceptives mainly affect the uterine and placental function: such drugs are still under research and have not yet used in large-scale. The main drug is prostaglandin.