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.”
