SHANGHAI - Supermarkets in major Chinese cities have taken Red Bull products off their shelves over fears that the energy drink may contain banned additives.

The scare was triggered by recent media reports in Harbin that stated that some of the beverage's ingredients are not registered with the State Food and Drug Administration (SFDA) and are not approved for vitamin functional beverages.

The ingredients include sodium benzoate, a preservative that, when combined with caffeine, may produce a substance considered an A-class drug for psychiatric treatment.

An overdose of the substance could cause headaches, stress, anxiety, tinnitus and addiction, said Dr. Zhang Jing from the First Hospital affiliated with the Harbin University of Medical Science.

Other additives found in Red Bull products, including sodium citrate, citric acid, carmine pigment and tartrazine, are also not registered with the SFDA, according to a list of Red Bull ingredients posted on the SFDA's website.

The SFDA and its provincial bureaus have launched an investigation, but have not ordered removal of the drinks as of Saturday.

Although Red Bull posted a statement on its website on Friday that insists its products are "safe" and "free of any banned additives," supermarkets in major Chinese cities, including Beijing and Shanghai, have pulled the drinks out of safety concerns.

A shelf that previously held cans of Red Bull was completely empty at a Tesco convenience store outlet on Shanghai's North Zhongshan Road, with only the price tags remaining.

A spokesman from Carrefour's Shanghai regional headquarters confirmed the retail giant has removed all Red Bull products from its shelves for safety reasons.