Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Feb 22;9(1):2582.
doi: 10.1038/s41598-019-39609-0.

Detection of cannabinoids in hair after cosmetic application of hemp oil

R Paul  1 , R Williams  2 , V Hodson  2 , C Peake  3
Affiliations

Detection of cannabinoids in hair after cosmetic application of hemp oil

R Paul et al. Sci Rep. .

Abstract

The detection of cannabis constituents and metabolites in hair is an established procedure to provide evidence of exposure to cannabis. We present the first known evidence to suggest that applying hemp oil to hair, as cosmetic treatment, may result in the incorporation of Δ9-tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and in one instance, the metabolite 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH). 10 volunteers treated their head hair daily with commercially available hemp oil for a period of 6 weeks. Head hair samples were collected before and after the application period. Hair samples were washed with methanol and subjected to clean up via liquid/liquid and solid phase extraction procedures, and then GC-MS/MS for the analysis of THC, CBN, CBD, THC-OH and THC-COOH. 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 and CBD. One volunteer showed low levels of the metabolite THC-OH. 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.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

References

    1. Cherney JH, Small E. Industrial Hemp in North America: Production, Politics and Potential. Agronomy. 2016;6:1–24. doi: 10.3390/agronomy6040058. - DOI
    1. Moosmann B, Roth N, Auwärter V. Finding cannabinoids in hair does not prove cannabis consumption. Sci Rep. 2015;5:14906. doi: 10.1038/srep14906. - DOI - PMC - PubMed
    1. Berthet H, et al. A systematic review of passive exposure to cannabis. Forensic Sci Int. 2016;269:97–112. doi: 10.1016/j.forsciint.2016.11.017. - DOI - PubMed
    1. Herrmann ES, et al. Non-smoker exposure to secondhand cannabis smoke II: effect of room ventilation on the physiological subjective and behavioural/cognitive effects. Drug Alcohol Depend. 2015;151:194–202. doi: 10.1016/j.drugalcdep.2015.03.019. - DOI - PMC - PubMed
    1. Musshoff F, Madea B. Review of Biologic Matrices (Urine, Blood, Hair) as Indicators of Recent or Ongoing Cannabis Use. Ther Drug Monit. 2006;28:155–163. doi: 10.1097/01.ftd.0000197091.07807.22. - DOI - PubMed