WEIGHT LOSS FOOD SUPPLEMENTS: ADULTERATION AND MULTIPLE QUALITY ISSUES IN TWO PRODUCTS OF CHINESE ORIGIN

One of the most serious quality issues associated with herbal products used for healthcare purposes is the deliberate adulteration with synthetic substances, meant to increase the efficacy of respective products in the claimed indications. Here we report on adulteration with sibutramine and phenolphthalein in two herbal food supplements of Chinese origin, widely distributed through internet in various countries, promoted for weight loss. An HPLC method developed and validated by the authors was used for the separation and assay of the two substances. The average content per capsule for one of the two products, determined through this method was 24.71 mg sibutramine and 48.20 mg phenolphthalein. We also determined flavonoids (through a spectrophotometric method), uniformity of mass (according to European Pharmacopoeia, 6th edition) and performed a microscopical examination of the capsule content. The results raised concerns regarding the quality of the two products. Furthermore, an analysis of the clinical and non-clinical data available in the scientific literature for the herbal ingredients of the two products has shown that it is very unlikely that, in the amounts of the current formulations and posology, the products have weight loss inducing effects.