WASHINGTON, D.C.: The Food and Drug Administration announced plans to curtail the marketing of weight-loss and muscle-building supplements containing ephedrine, a natural compound linked to hundreds of injuries and at least 17 deaths in the U.S. The crackdown will force manufacturers to limit the amount of the stimulant these substances can contain, force manufacturers to include labels warning that excessive use can cause death, and direct them to abandon claims that ephedrine helps users to build muscle and lose weight. The regulations will also prohibit manufacturers from recommending use for more than seven consecutive days. The move follows a recent FDA proposal which attempted to curb the use of Herbal Ecstasy, an ephedrine-based product which promised users a "natural high." Ephedrine supplements net between $15 and $30 million a year for leading manufacturers.