U.S. Food and Drug Administration decisions about ephedra-based drugs
Federal agency NCCAM's summary
about the same thing but in more simple language:
After a careful review of the available evidence about the risks and benefits of ephedra in supplements, the FDA found that these supplements present an unreasonable risk of illness or injury to consumers. The data showed little evidence of ephedra's effectiveness, except for short-term weight loss, while confirming that the substance raises blood pressure and stresses the heart. The increased risk of heart problems and strokes negates any benefits of weight loss.
There is no evidence that ephedra products enhance athletic performance. There is little evidence of any benefit except for short-term weight loss.