Potency Trends of Δ⁹‐THC and Other Cannabinoids in Confiscated Cannabis Preparations from 1993 to 2008*

TLDR

The University of Mississippi’s NIDA‑funded Potency Monitoring program supplies analytical potency data on confiscated cannabis in the United States. The program analyzed 46,211 seized samples by gas chromatography–flame ionization detection between 1993 and 2008. Across all preparations, mean Δ9‑THC rose from 3.4 % in 1993 to 8.8 % in 2008, while hashish potencies fluctuated from 2.5–9.2 % (1993–2003) to 12.0–29.3 % (2004–2008) and hash oil averaged 16.8 % ± 16.3 %, with the overall increase largely attributable to higher potency in nondomestic samples.

Abstract

Abstract: The University of Mississippi has a contract with the National Institute on Drug Abuse (NIDA) to carry out a variety of research activities dealing with cannabis, including the Potency Monitoring (PM) program, which provides analytical potency data on cannabis preparations confiscated in the United States. This report provides data on 46,211 samples seized and analyzed by gas chromatography‐flame ionization detection (GC‐FID) during 1993–2008. The data showed an upward trend in the mean Δ 9 ‐tetrahydrocannabinol (Δ 9 ‐THC) content of all confiscated cannabis preparations, which increased from 3.4% in 1993 to 8.8% in 2008. Hashish potencies did not increase consistently during this period; however, the mean yearly potency varied from 2.5–9.2% (1993–2003) to 12.0–29.3% (2004–2008). Hash oil potencies also varied considerably during this period (16.8 ± 16.3%). The increase in cannabis preparation potency is mainly due to the increase in the potency of nondomestic versus domestic samples.