In recent years, researchers have found significant differences among racial, ethnic and gender groups in the ways they respond to and metabolize drugs, and experience side effects. Most studies have focused on cardiovascular, psychotropic and central nervous system drugs. Alcohol, antihistamines and analgesics are other agents with varying effects among different racial, ethnic and gender groups. The Food and Drug Administration (FDA) noted last year that Asian-Americans show increased sensitivity to beta blockers. It also observed that African-Americans are less responsive to ACE inhibitors. Gender differences in drug therapy seem to basically evolve around psychotropic drugs. Environmental, cultural and genetic factors are involved in determining response to medicines in different racial, ethnic and gender groups. Continued research in this area will undoubtedly reveal significant information regarding racial, ethnic and gender differences in response to drugs. These developments will impact on how clinical trials are conducted and challenge conventional thoughts regarding restricted formularies.