One key legal question on everyone's mind is whether RU 486 can meet the standards for Food and Drug Administration (FDA) approval for a drug indicated for abortion. It would seem that it can. Under the Food, Drug, and Cosmetic Act, a sponsor must show that a drug is safe and effective for its intended use. Efficacy must be demonstrated by substantial evidence, which means evidence consisting of adequate and well-controlled investigations, including clinical investigations by experts qualified by scientific training and experience to evaluate the effectiveness of the drug. If on the basis of the clinical trials it could fairly and responsibly be concluded by such experts that the drug will have the effect it purports or is represented to have under the conditions of use prescribed in the labeling, and if the drug is safe, the FDA will approve it.