A new study has found that commercially available hemp seed oil products applied to hair can cause a positive result for cannabinoids on a hair follicle drug test.
The researchers conducted hair follicle drug tests on participants who had applied hemp seed oil to their hair for 6 weeks, NORML reported. The hemp seed oil did not contain detectable levels of THC and all participants declared they had not used or been exposed to cannabis.
“Application of hemp oil to hair resulted in the incorporation of one or more cannabis constituents in 89% of volunteers, and 33% of the group tested positive for the three major constituents, THC, CBN [cannabinol] and CBD [cannabidiol],” the researchers stated.
They also stated, “It is of concern that cannabinoids have been detected in hair samples following the application of hemp oil as a cosmetic procedure, and at levels in our study relevant to suggest cannabis exposure in some cases. … We suggest that cosmetic use of hemp oil should be recorded when sampling head hair for analysis, and that the interpretative value of cannabinoid hair measurements from people reporting application of hemp oil is treated with caution in both criminology and public health.”