Analysis of over-the-counter analgesics purported to contain mescaline from the peyote cactus (Lophophora williamsii: Cactaceae)

Résumé

The purpose of this study was to investigate samples of commercial over-the-counter products purported to contain extracts from peyote cactus (Lophophora williamsii), a vulnerable species. Samples were extracted with organic solvent and then washed to remove impurities. The extracts of these products were subjected to an analysis by real-time mass spectrometry (DART-MS) to determine the presence or absence of the alkaloid mescaline (3,4,5-trimethoxyphenethylamine). High-performance liquid chromatography (HPLC) was used to determine mescaline concentrations in the samples and to provide quantitative evidence of the concentration—if any—of mescaline in the products. If a detectable level of mescaline—a stable and abundant alkaloid of L. williamsii—was found in a given extract, then it was inferred that L. williamsii was present in the corresponding topical product. The results of this investigation show that most consumers who purchase the products in question are being defrauded if they believe they are buying L. williamsii-based medicines. The lack of mescaline—implying the lack of peyote—in these products suggests that wild populations of the vulnerable cactus L. williamsii, though currently being decimated on a massive scale in Mexico and the U.S. for other purposes, are rarely harvested for use in topical analgesic products. This conclusion is based on the finding that less than 5% of the ostensible L. williamsii-containing topical analgesic products that were analyzed in this study actually contained mescaline.