At least one folk-method of contraception is being looked into. A South American weed, Stevia rebaudiana, has traditionally been used by the Indians in Paraguay as a contraceptive. Each day women drink a cup of water in which the powdered weed has been boiled. Experiments with rats have indicated a reduction in fertility from 57 to 79 percent compared with a control group, with low fertility lasting up to two months after withdrawal of the drug. Undoubtedly many such folk-methods are known in various human cultures. Some of them may be quite effective and might prove adaptable to the urgent need for population control, particularly in underdeveloped countries.
– Anne Ehrlich and Paul Ehrlich, “Population. Resources, Environment: Issues in Human Ecology” (San Francisco: W.H. Freeman and Company, 1970), p. 227-228;
See also Paul R. Ehrlich, John P. Holdren, Anne H. Ehrlich, “Ecoscience: Population, Resources, Environment” (1978).
John Holdren is President Barack Obama’s science czar. Stevia is sold as a sweetener and sugar substitute extracted from the leaves of the plant species Stevia rebaudiana.