Much like the recreational dose, the overdose level is difficult to pin point because of differences between people. Deaths have been reported at levels as low as 1.3mg/kg (i.e., at a dose level equivalent to 1.3 milligrams of amphetamine per kilogram of the users bodyweight; e.g., in a 80kg human this would equate to a dose of 104mg), other reports state tolerance has been built up to 1 gram at a time and up to 5g in a day without being toxic to the user. These extremes indicate the variation of overdose levels. People who are allergic to a component of the substance ingested (recall that these 'drugs' are powdered mixtures which may have significant adulterants due to lack of any quality control in the synthesis procedure and overzealous cutting) or anaemic people have a higher risk of overdose at very low levels, while people who are frequent users may be able to withstand a much higher dose. Because of the difficulty in determining the overdose level it is important to be sensible with your consumption and to know your own limits. It is also important to be able to identify the symptoms of an overdose.
