CBD-THC-Ratio (Metaboliten) im Urin

Urine, 5ml

With the increase in commercial availability and use of CBD-containing products, healthcare providers are increasingly faced with the challenge of determining whether a positive drug test for cannabis was caused by the consumption of a CBD product or by the consumption of marijuana, medical THC or other THC products. This is particularly relevant for Switzerland, as legal CBD products here may contain up to less than one per cent by weight of the active ingredient d9-THC, i.e. an active ingredient content of 9.9 mg d9-THC in one gram of CBD cannabis flowers may be legally sold (see, for example, the website of the Federal Office of Public Health in Switzerland, BAG, Legislation on Hemp and Cannabis Products, Low-THC Hemp, published online on 4 March 2025). Regardless of this, such products can also be ordered online. This means that there is no guarantee that the product actually corresponds to the declaration. Higher levels of d9-THC could well be found in such products (see also S. Habel and colleagues, Positive cannabis urine tests due to commercial cannabidiol products, Toxichem Krimtech 2020; 87(1):10).
After measuring THC and CBD, including their metabolites (including glucuronides, following enzymatic and alkaline hydrolysis of the urine), the total concentrations are calculated and a ratio is derived from them. This ratio is intended to estimate the type of cannabis products consumed (CBD-rich or THC-rich products)*. The data are evaluated using a naïve Bayes classifier to assess the probabilities of different consumption patterns (e.g., CBD user, mixed CBD/THC cannabis use, THC user, or no meaningful classification possible). The classifier is based on the following publications [1–5].
*Interpretation is only possible in conjunction with clinical data. Absolute concentrations (e.g., very high THC-COOH levels) must also be taken into account, as the ratio may have limited significance in individual cases — for example, when THC-COOH levels in urine are very high (e.g., greater than 500 µg/L; see also “Residual Cannabis Levels in Blood, Urine and Oral Fluid Following Heavy Cannabis Use,” by M. D. Odell et al., FSI 2015, doi: 10.1016/j.forsciint.2015.01.026).

[1] M. M. Goggin & G. C. Janis, Using measured cannabidiol and tetrahydrocannbinol metabolites in urine to differentiate marijuana use from consumption of commercial cannabidiol products, Clinical Toxicology 2021, 59(6)
[2] U. Meier und Kollegen, Cannabinoid Concentrations in blood and urine after smoking cannabidiol joints, Forensic Science International 291 (2018), 62-67
[3] T. R. Spindle et al., Urinary Pharmacokinetic Profile of Cannabinoids Following Administration of Va-porized and Oral Cannabidiol and Vaporized CBD-Dominant Cannabis, Journal of Analytical Toxicol-ogy 2019; 1-17
[4] D. J. Sholler et al., Urinary Pharmacokinetic Profile of Cannabidiol (CBD), ∆9-tetrahydrocannabinol (THC) and Their Metabolites following Oral and Vaporized CBD and Vaporized CBD-Dominant Cannabis Administration, Journal of Analytical Toxicology 2021, 00: 1-10
[5] S. Vikingsson et al., Prevalence of Cannabidiol, ∆9- and ∆8-Tetrahydrocannabinol and Metabolites in Workplace Drug Testing Urine Specimens, Journal of Analytical Toxicology, Volume 46, Issue 8, October 2022, Pages 866–874, https://doi.org/10.1093/jat/bkac013