Quantitative Analysis of Mitragynine in Consumer Products Labeled as Kratom

Mitrgyna speciosa is a tropical evergreen tree native to Southeast Asia. The leaves of this tree are referred to as kratom and contain over 35 alkaloids of which some have been reported to have stimulant and analgesic properties. The two most prominent of these alkaloids are mitragynine and 7-hyrdroxymitragynine. Recently, consumer products labeled as kratom have been gaining popularity in the U.S. and are not currently regulated by the FDA. In order to determine if these products contained mitragynine and/or 7-hydroxymitragynine, as well as a third alkaloid paynantheine, qualitative and quantitative analysis were completed using an Agilent 6890N gas chromatography instrument with an Agilent 5975 mass spectrometer. 32 products were tested of which 22 were in powder form, 5 were capsules containing powder, and 5 were in a liquid form. All 32 products contained mitragynine, 30 of which could be quantified. They ranged in concentration from 3.2 to 12.5 g/mg. 13 of the 32 products had detectable levels of 7-hydroxymitragynine, 7 of which could be quantified. They ranged in concentration from 2.02 to 2.03 mg/g. 30 of the 32 products had detectable levels of paynantheine, 23 of which could be quantified. They ranged in concentration from 2.3 to 6.7 mg/g. The labeling of these consumer products was found to be true in that they did contain kratom. However, products that were labeled with a specific concentration of mitragynine and 7-hydroxymitragynine were found to be much lower than the label. In addition, the strength and potency advertised by the “strain” was found to be inconsistent between brands with no clear indicator of any difference between them.