I get high off about .1 grams out of my one hitter depending on quality so im sure you will get high many times off 1.5 grams depending on how many people you smoke with and what you smoke out of. I didn't get high until many many times after my first time using it. Maybe The first time I got high was off of some reallllly skunky smelling weed, strongest I have ever smelled by far to this day, 1 gram in 3 ziplock bags could stink up a whole room. At the time I could get high probably 20 times off of that gram but i ended up flushing about 3/4 of it down the toilet while high because i kept thinking my mom would come home any minute and find it.