Last updated on: 4/13/2015 8:03:34 AM PST
Does Higher Potency Make Marijuana More Dangerous?


General Reference (not clearly pro or con)

General Reference

[Editor's Note: ProCon.org compiled a table of marijuana potency from 1975-2003. The data was tabulated from the Annual Reports of Mahmoud A. ElSohly, Ph.D., Director of the National Institute on Drug Abuse (NIDA) Marijuana Project at the National Center for Natural Products Research, School of Pharmacy, University of Mississippi. See NIDA's chart in PDF format.]

THC% By Decade: THC% By Period:
1970's - 1.08% 1975-1984 - 1.93%
1980's - 2.83% 1985-1994 - 3.06%
1990's - 3.76% 1995-2003 - 4.92%
2000's - 5.73%  




PRO (yes)

Mahmoud ElSohly, PhD, Research Professor at the Research Institute of Pharmaceutical Sciences at the University of Mississippi, told the Washington Post in a June 4, 2002 article:

"This [marijuana] is a drug that produces tolerance. The smoker has to increase the amount he uses, just like alcohol.

High-potency pot ups the ante, producing a higher tolerance more quickly; and such higher levels of THC, quickly pumped into the body, can be great enough to induce the drug's more negative effects."

June 4, 2002 - Mahmoud A. ElSohly, PhD 



Andrea Barthwell, MD, former Deputy Director at the US Office of National Drug Control Policy (ONDCP), told an audience on Jan. 26, 2005:

"[I]n the 1970s and 80s, the active ingredient in marijuana, THC, was at 3.5 percent. Today, the THC found in most marijuana averages more than 7 percent. But specific techniques can skyrocket the amount of THC to as high as 27 percent.

The higher the THC gets, the more rapidly you deliver a large jolt of the active ingredient to the brain. Today's marijuana is much more powerful and much more addictive than it was a generation ago."

Jan. 26, 2005 - Andrea Barthwell, MD 



Wilson M. Compton, MD, Director of the Division of Epidemiology, Services and Prevention Research at the National Institute on Drug Abuse (NIDA) at the time of the quote, et al., wrote the following in their May 2004 article "Prevalence of Marijuana Use Disorders in the United States: 1991-1992 and 2001-2002," published in the Journal of the American Medical Association (JAMA):

"[M]arijuana use disorders among marijuana users significantly increased in the absence of increased frequency and quantity of marijuana use, suggesting that the concomitant increase in potency of delta-9-THC [one of the active ingredients in marijuana] may have contributed to the rising rates...

[M]arijuana abuse or dependence increased among marijuana users by 18% from 30.2% in 1991-1992 to 35.6% in 2001-2002... The potency of delta-9-THC in confiscated marijuana from police seizure increased by 66% from 3.08% in 1992 to 5.11% in 2002... there was no systematic change in the frequency of marijuana use between 1991-1992 and 2001-2001...

Increasing rates of marijuana use disorders among marijuana users in the absence of increased quantity and frequency of use strengthens the argument that the increasing rates may be attributable, in part, to increased potency of marijuana."

May 2004 - Wilson M. Compton, MD 



CON (no)

The National Institute on Drug Abuse (NIDA) stated in a June 4, 2002 article in the Washington Post:

"Data from an ongoing project called 'Monitoring The Future' supports the notion that smokers aren't getting higher from more potent joints.

Surveys show that joint sizes have dropped over the years from half a gram to about a quarter of a gram because more experienced smokers know that a smaller amount of pot can go a longer way toward making the smoker high."

June 4, 2002 - National Institute on Drug Abuse (NIDA) 



Lester Grinspoon, MD, Professor of Psychiatry at Harvard Medical School, stated in a June 4, 2002 article in the Washington Post:

"The whole issue on potency is a red herring. The more potent the pot, the less you use...

Marijuana users smoke until they achieve symptom relief, and then stop, whether it took two hits or an entire joint. In this regard, today's higher-potency pot is no more 'dangerous' than the bunk weed of yesteryear."

June 4, 2002 - Lester Grinspoon, MD