i know theres a pure sativa strain out there thats 22% thc but takes 120 days to flower i dont know wot its called or who buy but its available at my local grow shop an in feminized so should be easy to find out what it is
otherwise you can get reaaly high thc content from strains like blueberry, maza, white widow, euforia an theres loads more the best thing to do is go for a sativa an harvest a lil bit earlier when trichomes are all milky an a couple clear thatl give ya a more head high