The unapproved drug centrophenoxine (meclofenoxate) in cognitive enhancement dietary supplements.

INTRODUCTION: Centrophenoxine (meclofenoxate) is prescribed in China and elsewhere to treat a variety of conditions including alcoholism and dementia, but the US Food and Drug Administration has not approved the drug for any indication. We designed our study to determine the presence and quantity of centrophenoxine in dietary supplements sold over-the-counter in the US.

METHODS: Supplements were included in our study if the label included (a) the term "dietary supplement" and (b) "centrophenoxine" as a declared ingredient. Supplements were purchased online, and powder from each dietary supplement product was reconstituted in methanol and analyzed using ultra high-performance liquid chromatography.

RESULTS: Seven products were analyzed. Centrophenoxine was present in all products in dosages ranging from 79 to 251 mg per serving. Consumers following the maximum recommended daily intake on the label would be exposed to 237 to 752 mg of centrophenoxine per day. Only 1 of 7 products (14%) listed a quantity of centrophenoxine on the label within ±10% of the actual amount.

CONCLUSION: Clinicians should be aware and advise patients that cognitive enhancement supplements may contain unapproved and prohibited drugs.