Depending on the concentration, form, and method of administration, recreational doses of ketamine range from 30 - 300 mg. The dosage range for insufflated (snorted) ketamine varies widely from about 15-200 mg. With doses higher than about 50 mg it is advisable to be lying down. I.M. (intra-muscular injections) ketamine dosages are generally between 25-125 mg. Oral use usually requires more material, ranging from 75-300 mg.