Delta-8-tetrahydrocannabinol is a popular psychoactive cannabinoid found in the Cannabis plant. It is an isomer of delta-9 tetrahydrocannabinol, the compound commonly known as THC. ∆8-THC products can be found almost everywhere for purchase. Another reason for Delta-8’s growing popularity is that, unlike heavily regulated THC, Delta-8 is legal to use in most states. That’s because it’s extracted mostly from hemp-derived CBD, which is legal to farm across the U.S.