Frequently Asked Questions (and their answers) for Notice of Information: Establishment of a Standard THC Unit To Be Used in Research
- Are there standard units defined for constituents other than delta-9-THC in cannabis and cannabis-related products?
The standard unit of 5mg THC is specific to delta-9-THC and does not apply to other cannabis constituents, for which standard units have not been established.
- Should the quantity of other significant constituents (including cannabinoids and non-cannabinoids), if any, be reported along with the standard units of delta-9-THC in cannabis and cannabis-related products?
Other significant constituents should be reported as they typically would be, as relevant to the specific research project.
- Is there a requirement to report other information about cannabis and cannabis-derived products, such as source, packaging, certificate of analysis, etc.?
The new requirement pertains only to the amount of delta-9-THC in a product. Other information can be reported as well, if relevant to the specific research project.
- Does the Notice limit the use of a specified cannabis product, e.g., synthetic vs natural delta-9-THC?
No, the Notice does not restrict or mandate the use of any particular THC product.
- How should pharmacokinetic exposure metrics for cannabis and cannabis-related products be reported?
The standard unit is to be used when reporting the amount of delta-9-THC administered to or consumed by research participants. The pharmacokinetic parameters, such as the concentrations of THC in biological matrices (e.g., blood, plasma, serum), are reported using conventional units (e.g., ng/mL, ng.hr/mL).
- Is the standard THC 5 mg unit the minimum unit one should use? Can one use higher or lower amounts for their research experiments?
The standard THC unit does not place a limit on how much delta-9-THC researchers can use in experiments nor does it indicate safety or endorse any specific amount as advisable for administration or consumption by research participants. Investigators are free to use more or less than 5 mg THC as appropriate for their research experiments, but results should be expressed in multiples (or fractions) of the standard 5 mg THC unit used.
- In which documents are investigators expected to use standard units?
Investigators are expected to use the standard THC unit in their applications, research performance progress reports, and dissemination of their results through publications, posters, and other materials. This does not preclude the additional reporting of results using other measures (e.g., milligrams of delta-9-THC) as appropriate to the research project.
- I’m in the process of revising and resubmitting a research proposal. In my resubmission, am I required to report the amount of delta-9-THC I plan to use in the standard unit?
Yes, you should report the amount of delta-9-THC using the standard unit in your resubmission as well as in new grant applications.
- Can you provide an example to illustrate how the standard unit should be implemented?
The standard THC unit is to be used when reporting the amount of delta-9-THC administered to or consumed by research participants. Implementing the standard unit requires conversion of the amount of delta-9-THC administered or consumed from milligrams to standard THC units. For example, 10mg THC would be 2 standard THC units. If researchers are administering or participants are consuming THC in increments other than 5mg, they would need to report that in standard units. For example, 16mg THC = 3.2 standard THC units. Suggested abbreviation for standard THC unit: STU.
- How should researchers report delta-9-THC quantities in cases where exact concentrations or dosage may not be available, such as dispensary data, electronic health records, surveys, or administrative datasets?
It is understood that it may not be possible to report delta-9-THC standard units for all research questions—especially epidemiological research, where consumers may not be aware of the quantities of THC they are consuming. Researchers will need to provide a justification for not using the standard THC unit; e.g., a specific dataset or survey instrument may not provide the necessary information to convert the amount of THC used into the standard THC unit.
- I am not applying to/funded by one of the Institutes issuing this Notice. Am I expected to use the standard unit in my application, research performance progress report, or research publication?
Researchers applying to/funded by other ICs may want to consider using the standard THC unit when reporting their results as appropriate to the research project but are also advised to check with the appropriate program officer in the Institute in question, in order to make that determination.