More THC, less CBD in confiscated cannabis

By Paul Armentano, NORML

Levels of the cannabinoid CBD (cannabidiol) are declining in marijuana, according to a review* of over 5,000 samples seized by law enforcement in California. The review appears on the website of the journal Drug and Alcohol Dependence.

Investigators at the RAND Corporation in Santa Monica assessed changes in the median THC and CBD levels of cannabis seized between 1996 and 2008 and found that THC levels rose during this time peri- od while CBD levels fell.

“[M]edian THC potency has increased from 4.56% in 1996 to 11.75% in 2008,” they reported. “The increase in THC was far more dramatic in non-border areas (from 4.18% to 13.95%) than in border areas (from 4.52% to 6.84%). … The median level of CBD dropped from 0.24% in 1996 to 0.08% in 2008.”
The authors speculated that the shift was because “growers are making greater use of plant strains that favor THC production over CBD production.”

Cannabidiol is a non-psychotropic cannabinoid that is believed to temper the psychoactive effects of THC. In preclinical trials, CBD has demonstrated the ability to both treat symptoms and modify the course of various diseases. A recent review in the journal Trends in Pharmacological Sciences reported that CBD has over a dozen separate therapeutic properties — including anti-cancer, anti-diabetic, anti- epileptic, and anti-bacterial.

A small number of growers has recently begun breeding ‘CBD-rich’ strains of
cannabis (defined as 4% CBD or higher) for the medical market. Information on these strains, CBD content, and availability is posted online at

* “Heterogeneity in the composition of marijuana seized in California” appears in Drug and Alcohol Dependence.

1 comment to More THC, less CBD in confiscated cannabis

Leave a Reply




You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>