i recently had a physical exam for a life insurance policy. blood test & urine. i spark about 1-2x a week. i abstained for 16 days and tested clean. worked out a ton & sweated. ate clean. i picked up some of those thc test kits. they are like $2 a pop. they work. if you grill everyday i would allow for at least 3 weeks before the test. if you are not active and are overweight allow for at least a month if not more.