The University of Mississippi has a contract with the National Institute on Drug Abuse
to carry out a variety of research activities dealing with cannabis, including the
Potency Monitoring (PM) program that provides analytical potency data on cannabis
preparations confiscated in the United States. This report provides data on 46,211
samples seized and analyzed during 1993–2008. The data showed an upward trend in the
mean Δ9-THC content of all confiscated cannabis preparations, which increased from 3.39%
in 1993 to 8.78% in 2008. Hashish potencies did not increase consistently during this
period; however, the mean yearly potency varied from 2.52–9.23% (1993–2003) to 11.98–29.33%
(2004–2008). Hash oil potencies also varied considerably during this period (16.76±16.32%).
The increase in cannabis preparation potency is mainly due to the increase in the
potency of non-domestic versus domestic samples. There was no significant change in
the potencies of CBC, CBD, CBN, CBG and THCV. Acknowledgement: This work was supported with federal funds from the National Institute of Drug Abuse
(NIDA), National Institute of Health (NIH), Department of Health and Human Services,
USA, under the contract No. N01DA-7–7746.