Cooking with Keif

I have friend that adds about an 1/8 to a batch of brownies but last batch he cooked butter with a gram of keif. He says there strong but im about twice his size and i never catch a buzz. What a normal about to add to an batch of brownies?

I just bought this AWSOME book called Cooking with Keif: A Gourmet Medicinal Marijuana Experience by Scott Bottjer...... You should pick it up..... He has a wonderful recipe on creme brulee with keif.... and one with tiramisu..... along with some great entree's..... you should pick this up great ratios for infusions not overpowering......