This is a cautionary report about HHC and drug testing. I switched from Delta-9 cannabis to HHC specifically because I read online that HHC does not show up on drug tests. Multiple vendors and Reddit posts claimed that because HHC is a different molecule than THC, its metabolites would not trigger the standard immunoassay cannabis screen. This turned out to be wrong, and it nearly cost me my job.
I used an HHC vape cart nightly for about two weeks -- 3-4 puffs each evening, estimated 10-15mg per session. I had stopped using Delta-9 cannabis three weeks before starting HHC, so any THC should have been well out of my system.
On a Monday, my employer announced a random drug screening. I was selected. I was not worried because I had been told HHC was undetectable.
The immunoassay came back positive for cannabinoids. I was shocked. My employer gave me the option to have the sample sent for confirmatory GC-MS testing, which I requested, hoping the confirmatory test would distinguish HHC metabolites from THC metabolites and clear me.
The confirmatory test was more nuanced — the lab noted the presence of metabolites consistent with HHC use rather than Delta-9-THC use. However, my employer's drug policy did not distinguish between THC and HHC. As far as their policy was concerned, a positive cannabinoid screen was a positive cannabinoid screen. I was placed on probation and required to complete a substance abuse evaluation.
What I learned afterward: HHC is metabolized to 11-hydroxy-HHC and then to HHC-COOH (11-nor-9-carboxy-hexahydrocannabinol). The HHC-COOH metabolite is structurally similar enough to THC-COOH that it cross-reacts with the antibodies in standard immunoassay cannabis drug tests. The claims that HHC is invisible to drug testing were marketing, not science.
If you are subject to drug testing for employment, probation, athletics, military service, or any other reason, do NOT use HHC under the assumption that it will not be detected. It very likely will be. I learned this the hard way and I am writing this so others do not have to.