The federal agency said the product, sold as an "all-natural herbal supplement for male performance" might contain an unlabeled prescription drug phentolamine, which is only authorized for intravenous use to prevent and control high blood pressure in patients with adrenal tumors.

Health Canada said new lab results indicate two lots -- 84881 and 0070263 -- of the product contain phentolamine, which when used by patients with heart disease can potentially result in serious cardiac side-effects.

Desire is labeled as manufactured by Desire LLC, and distributed by StarChem Labs of Farmingdale, N.Y. The product is sold across Canada and on the Internet.