United States: THC standard dose established for cannabis research

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

The notice defines a standard unit of THC 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 results across studies«.

Although subjects may experience different effects, even when consuming the same amount of THC, due to the route of administration, other elements of the product, an individual's genetic make-up and metabolic factors, previous exposure to cannabis and other contributing factors, the aim of the notice is to increase the comparability of cannabis studies.

The standard does not require researchers to administer more or less than 5 mg of THC during studies, and will not apply to other psychoactive cannabis molecules such as cannabidiol (CBD). It is conceived as a unit of measurement, just as alcohol research has established a standard dose of 0.6 fluid ounces (1.77cL) of pure alcohol.

«Adopting a standard unit for measurement and reporting will facilitate data interpretation and enable the design of drug effects experiments that are relevant in the real world, while also facilitating the application of this research to policy and clinical practice,» wrote Nora Volkow, director of the National Institute on Drug Abuse, and Norman E. Sharpless, director of the National Cancer Institute, in a blog post published May 10, 2021 regarding the notice.

«Our hope is that the adoption of this 5 milligram standard will lead to a better understanding of the effects of THC by researchers as well as the general public.»

In the recreational market, a dose for an adult is usually defined as 10mg THC per serving.