The court's decision, issued without comment, lets stand a 2006 ruling by a federal appeals court that upheld the Food and Drug Administration's 2004 ban.

Nutraceutical executives did not respond Monday to repeated requests for comment. The company's shares fell 3 cents, to $16.15.

Ephedra was marketed in the 1980s and 1990s as a weight-loss supplement and an aid to athletic performance. The FDA began receiving reports in the late 1990s of major side effects from ephedra use, including heart attacks, strokes and death, according to court papers filed by the government.

The FDA banned the supplement after determining that it presented an unreasonable risk of illness or injury at any dose.

In challenging the ban, Nutraceutical argued that ephedra did not present significant risks at the low dosage levels it recommended, and charged that the FDA did not fully investigate the herbal supplement's effects at lower levels of use.

The 10th Circuit Court of Appeals ruled last year that the FDA had acted properly when it imposed the ban.

The agency ''found that the weight loss and other health benefits possible from the use of [ephedra] were dwarfed by the potential long-term harm to the user's cardiovascular system,'' the appeals court said.