Hexahydrocannabinol (HHC) is a semi-synthetic cannabinoid derived from hemp. It is a hydrogenated form of Tetrahydrocannabinol (THC), meaning its chemical structure is nearly identical to THC but with an added hydrogen bond, which provides greater chemical stability. HHC is marketed as a legal alternative to Delta-9 THC, but its structural similarity raises a direct question for anyone subject to mandatory screening: can HHC be detected in a standard urine drug test?
How Standard Urine Drug Screens Work
Common workplace and clinical drug screens for cannabis rely on an initial immunoassay (IA) test because it is rapid and cost-effective. This screening method does not look for the active compound Delta-9 THC, but rather for its primary, inactive metabolite: 11-nor-9-carboxy-THC (THC-COOH). The immunoassay uses antibodies designed to bind specifically to the THC-COOH molecule in the urine sample.
If the concentration of the target metabolite exceeds a set threshold, typically 50 nanograms per milliliter (ng/mL), the test registers a positive result. Because these tests rely on the binding affinity of antibodies, they are prone to cross-reactivity. If another compound in the urine is structurally similar enough to THC-COOH, the antibody may mistakenly bind to it, leading to a presumptive positive screen result.
HHC Metabolism and Metabolite Formation
The body processes HHC through a metabolic pathway that closely mirrors the breakdown of Delta-9 THC. HHC is primarily metabolized in the liver by the cytochrome P450 enzyme system, which makes the compound more water-soluble for excretion. This process involves oxidation at a specific carbon chain position on the molecule.
This metabolic process produces a structurally analogous compound: 11-nor-9-carboxy-hexahydrocannabinol (HHC-COOH), rather than Delta-9 THC’s signature metabolite (THC-COOH). The hydrogenation that distinguishes HHC from THC is preserved in the metabolic byproduct. HHC-COOH is the true breakdown product that appears in the urine after HHC consumption, serving as the basis for HHC’s detectability.
Cross-Reactivity in Screening and Confirmatory Tests
Due to the structural kinship between HHC-COOH and THC-COOH, the initial immunoassay screen is highly likely to register a positive result following HHC use. The antibodies in the screening test cannot reliably distinguish between the two carboxy-metabolites, leading to a cross-reactive positive. This result is often referred to as a false positive for THC, as the person consumed HHC, not Delta-9 THC. HHC metabolites exhibit significant cross-reactivity with commercial cannabinoid immunoassays.
If the initial screen is positive, the sample is forwarded for confirmatory analysis using highly specific techniques like Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/Mass Spectrometry (LC/MS). These advanced methods chemically identify the exact molecule present. They can easily differentiate between THC-COOH and HHC-COOH, preventing a final report that incorrectly identifies Delta-9 THC use. The presence of HHC-COOH can still be identified and reported as a non-THC cannabinoid metabolite, confirming HHC consumption.
Variables That Affect Detection Duration
The length of time HHC metabolites remain detectable in urine depends on several physiological and usage factors. Dosage is a major variable, with higher intake leading to a greater concentration of metabolites that take longer to clear the system. The frequency of use is also paramount; chronic users accumulate the fat-soluble metabolites in adipose tissue faster than the body can eliminate them. Individuals with a higher percentage of body fat tend to store cannabinoids for longer periods, gradually releasing the metabolites back into the bloodstream. Metabolic rate and hydration levels also influence the excretion timeline. For heavy, chronic users, detection can potentially extend for up to 30 days or longer, mirroring the detection window observed for Delta-9 THC.