4 ounce shall do u well 5 will give u a really really bad ass trip im 180 and 3 and half got me fine. 5 or 6 is u want to be like crazy, when i do it, i try and pour it into a 1 oz shot glass and pour it so its almost in my throat already hits only the back of my tounge. then as fast as i can i take a swig of vernors or w/e and do the same thing 3 more times, prevents me from hurling i only do it once a month,, or maybe once every 3 weeks