i think 175-200mg is my sweetspot with K used IM. But rule of thumb for firsties, do 10mg up each nostril every 5-10 minutes until you get the feel of it. K lasts about 20 minutes so no matter how crazy your mind gets on you know you will be sober again in 20 minutes and enjoy your own private fantasy. Sweetest drug research i've had in a decade, those Ketamax vials from peaceandlove....cheap, reliable and full of experience.