However, The Food and Drug Administration and The American Health Regulatory Authority recently reinstated the drug because twenty years of human experience in those countries, which did not prohibit its use, had convinced the Food and Drug Administration that Depo-Provera did not cause cancer in humans. Another example that is even more bizarre is the drug Tamoxifin, which is used to treat human breast cancer. Even though Tamoxifin reduces the incidence of mammary cancer in rodents, it actually increases the presence of liver cancer in rodents, and appears to be also toxic to the kidney (Menache, 1998). .
Due to the unavoidable biological differences between human beings and animals, the results of animal tests can't be applied to human beings with any degree of confidence. At the 1989 scientific workshop held at the Ciba Foundation past scientific director of Huntington Research Center (U.K.) stated that the best guess for the correlation of extreme reactions in man and animal toxicity data is somewhere between 5% and 25%. The information translates into unacceptable risk levels for the general consumer public. To illustrate this point, the General Accounting office in the United Stated reported that between the years 1976-1985, out of two hundred medications introduced over that period of time, 51% were either withdrawn from the market completely or else re-labeled, because of severe side effects not previously noticed. .
The Food and Drug Administration has been faulted on animal drug data. In a report to Congress in 1992, the General Accounting Office found that the Food and Drug Administration in many instances did not carry out inspections to verify the accuracy of data given by private laboratories. Due to FDA's incompetent management the agency was unable to fulfill its task to protect the safety and health of animals and people (Menache, 1998). .
Professional groups of medical doctors, like the Medical Research Modernization Committee, are now at the cutting edge on the scientific movement advocating that animal tests be replaced with the new methodologies.
