Standard unit of THC established for cannabis research

On May 7, 2021, the National Institute on Drug Abuse, National Cancer Institute, the National Heart, Lung, and Blood Institute, and the National Institute of Mental Health published a joint notice in the National Institutes of Health Guide to establish a standard THC unit to be used in research studies funded by these institutions.

The notice defines a standard THC unit as “as any formulation of cannabis plant material or extract that contains 5 milligrams of THC.”

According to the notice, “inconsistency in the measurement and reporting of THC exposure has been a major limitation in studies of cannabis use, making it difficult to compare findings among studies.”

While subjects may experience different effects, even when consuming the same quantity of THC due to route of administration, other product elements, an individual’s genetic make-up and metabolic factors, prior cannabis exposure and other contributing factors, the goal of the notice is to increase the comparability of cannabis research studies.

The standard does not require that researchers administer no more or less than 5mg of THC during studies. It is intended as a unit of measure, much like research on alcohol has established a standard drink as 0.6 fluid ounces of pure alcohol.

“Adoption of a standard unit for measuring and reporting purposes will facilitate data interpretation and will make it possible to design experiments on drug effects that have real-world relevance, as well as make it easier to translate that research into policy and clinical practice,” wrote National Institute on Drug Abuse Director Nora Volkow and National Cancer Institute Director Norman E. Sharpless in a May 10, 2021, blog post regarding the notice.

“Our hope is that adopting this 5-milligram standard will enable a clearer understanding of the effects of THC by researchers as well as the wider public.”