On Tuesday the Food and Drug Administration (FDA) sent out a stern warning to consumers to avoid taking a product called Japan Rapid Weight Loss Diet Pills due to the discovery of a suspected cancer-causing agent present in them.

Japanese weight loss pills dangerThese pills (pictured right) are sold online from popular stores including Amazon and are distributed by a company called Xiushentang. The pills come packaged in three different colors (blue, green and yellow) in distinctive packs with Japanese writing all over the box and an image of a very thin woman. The advice from the FDA is for consumers to stop using these pills immediately and if there are any present in the household they should be discarded safely.

In a statement provided by the agency, it was confirmed by analysis in the FDA lab that the Japan Rapid Weight Loss Diet Pills Green contain undeclared phenolphthalein. According to the warning, the agent (phenolphthalein) is classified by the FDA as not generally recognized as safe and effective and has the potential to cause DNA damage or mutations

“Phenolphthalein is a solution used in chemical experiments and a suspected cancer-causing agent that is not approved for marketing in the United States.”

There were similar notices for other variations of the pills. Japan Rapid Weight Loss Diet Pills Yellow contain both phenolphthalein and sibutramine, the latter being a weight loss agent that was present in the drug Meridia. Meridia was removed from the market in 2010 due to the discovery that it increased risk of heart attack and stroke.

A third variation of the product, Japan Weight Loss Blue has been found to contain sibutramine and ephedrine alkaloids which have led to the banning of weight loss products due to their potential to increase blood pressure to high risk levels.

According to the agency, there has been an emerging trend where companies are selling weight loss pills marketed as dietary supplements that contain hidden ingredients that are potentially harmful to health.