Is today’s marijuana more potent?

Drug Policy Question of the Week – 9-19-10

As answered by Mary Jane Borden, Editor of Drug War Facts for the Drug Truth Network on 9-19-10.

Question of the Week: Is today’s marijuana more potent?

The DEA states on it’s website that,

“Although marijuana grown in the United States was once considered inferior because of the low concentration of THC, advancements of plant selection and cultivation have resulted in higher THC contained in domestic marijuana.”

A 2004 report called, “An Overview of Cannabis Potency in Europe,” from the EMCDDA [European Monitoring Centre for Drugs and Drug Addiction] says that,

“The information on which the claims have greatly increased cannabis potency have been made is not always clear.”

To clarify the issue, officials in the United Kingdom have issued the “Home Office Cannabis Potency Study 2008.” It found that,

“The mean THC concentration potency in sesamia samples was 16.2%” and that the “mean THC concentrations potency of traditional imported cannabis samples was 8.4%.”

From the last 420 Drug War News show, we recall that the Dr. ElSohly of the University of Mississippi has been analyzing seized cannabis samples since 1985. Potency percentages from his 2009 report are currently listed as Fact #14 in the Drug War Facts Marijuana chapter.

Using the data to reduce peaks and valleys, finds a three year average potency from 2005-2008 for sensimilla was 11.2% THC and for herbal marijuana, 5.8% THC. The three year average percentage change in cannabis potency was +3.9% for commercial marijuana and  –1.3% for sensimilla.

That European Monitoring Centre Report explains the difference between the US and British data by concluding that,

“It most be assumed that the quality of herbal cannabis consumed in the US more than 20 years ago was unusually poor but that in recent years, it has risen to levels typical of Europe.”

These facts and others like them can be found in the Marijuana chapter of Drug War Facts at

Questions concerning these or other facts concerning drug policy can be e-mailed to