Canada — Health Canada is warning consumers not to use V-King (Extra)® capsules. Promoted as natural health products, they may contain sildenafil citrate, a prescription-only drug approved for male erectile dysfunction. Inappropriate use of sildenafil can cause severe adverse reactions and the drug should not be used by persons taking nitrate-containing products concurrently since this could result in the development of potentially life-threatening low blood pressure.
The labelling indicates the ingredients as Harp seal reproductive organ extracts, traditional Chinese herbs, and supplements. V-King® has not been assessed by Health Canada, which attributes an eight-digit drug identification number on licensing.
Reference: Health Canada warning dated 20 January 2000. http://www.hc-sc.gc.ca