A Positive THC Urinalysis From Hemp (Cannabis) Seed Oil

Most varieties of hemp (i.e., non-drug Cannabis sativa L.) have very low levels of tetrahydrocannabinol (THC), typically less than 1.0%, although other cannabinoids may still be present in considerable amounts. Even though the seed does not contain measurable amounts of any cannabinoid, trace amounts of THC have been detected in some samples of hemp seed oil, apparently from the contamination of pressed seed by adherent resin or other plant material. We would like to report on the possibility of achieving a positive urinalysis for THC metabolite(s) after the modest consumption of commercially available hemp seed oil in Cannabis-naive individuals. Because hemp seed oil is an excellent source of essential fatty acids (EFAs, i.e., linoleic and linolenic acids), it is sold in some stores as a dietary supplement for these and other biologically important unsaturated fatty acids. Thus, in the absence of recreational drug use, it may become necessary to consider this source as a viable explanation for cannabinoid metabolites in urine. The importance of this distinction was recently highlighted in an article that reported a positive urine test for THC metabolites after the consumption of a commercially available snack that contained hemp seeds. Considering the lipophilic sequestering of THC and other cannabinoids, we were interested to know if modest consumption of hemp seed oil would result in a positive urinalysis for THC with standard laboratory methods. In the present report, two individuals who had not used any other form of Cannabis consumed various amounts of commercially available hemp seed oil, which was purchased from the refrigerate section of health food stores in the Miami area. Initial urine samples, which were collected before consumption of any hemp seed oil, gave negative results by EMIT.