HHC is a THC relative long known to science, but until recently not often discussed by cannabis users. HHC is a minor cannabinoid; it occurs naturally in cannabis, but in amounts too small to make extraction cost-effective. Since commercial production of HHC is just getting off the ground, it’s still not widely known.
Most cannabinoids can be converted to other cannabinoids by altering the chemistry of the molecules. Like delta 8 THC and delta 10 THC, commercial HHC is made from hemp-derived CBD in a lab through chemical processes. HHC has one major legal advantage over delta 8 and delta 10: it isn’t called THC.