Standard THC unit to be used in all future US cannabis research

The US government has introduced a standard THC measure that will be now be used across all applicable cannabis research.

The decision from the National Institute of Health aims to improve the comparability of cannabis research.

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 across different studies.

Now, the US federal health agency, has established a standard dose of THC which aims to provide greater consistency in the field of cannabis research.

US research applicants were informed last week of a new requirement to measure and report results using a standard THC unit in all applicable research on human subjects.

The standard THC unit has been defined as any formulation of cannabis plant material or extract that contains 5 milligrams of THC. This requirement now applies to applications proposing research on cannabis or its main psychotropic constituent, THC.

The notice was issued as a joint statement from the National Institute on Drug Abuse (NIDA), National Heart, Lung, and Blood Institute (NHLBI), National Institute of Mental Health (NIMH) and the National Cancer Institute (NCI)

The NIH said in a statement: “A standardised measure of THC in cannabis products is necessary to advance research by providing greater comparability across studies of both its adverse effects and potential medical uses.

“NIH recognises that the same quantity of THC may have different effects based on route of administration, other product constituents, an individual’s genetic make-up and metabolic factors, prior exposure to cannabis, and other factors.”

According to the NIH, the notice aims to increase the comparability of cannabis research studies, a goal that the agency says is a top priority for NIDA leadership and the National Advisory Council on Drug Abuse.

The selection of 5 mg as a standard unit was based on ‘extensive’ stakeholder input, including a Request for Information to the general public and consultations with experts in the field.

This guidance will apply to applications where THC is a focus of the research. Applicants are responsible for determining whether the use of the standard unit is applicable to their research and for determining the best approach to applying it in their research.

The NIH states that it is “not the intent of this notice to prescribe the quantity of THC that is permissible for use in research projects”, meaning investigators are free to use more or less than 5mg of THC in their studies where appropriate. Those that do not use the standard unit, however, will have to provide a justification to the NIH.