This hybrid has potentially massive THC levels, upwards of 30%. That makes it a favorite of medical marijuana patients seeking treatment for their stress and chronic pain. Black Jack has an indica/sativa ratio of 30:70, a result of its Black Domina and Jack Herer genetics. To be clear, there are actually two strains called Black Jack, including a second hybrid that descends from Black Domina and a European local known as Jock Horror. The latter strain is known as Blackjack, though it’s quite similar to the original Black Jack. CBD levels are low in Black Jack, so this strain isn’t recommended for seizure disorder. But it is recommended for use in treating anxiety, depression, and mood disorders, as well as nausea and lack of appetite. The strain can also be helpful in fighting insomnia. The indica genes create a potent, euphoric body high with deep relaxation.