Matt Vogel, a health promotion specialist from Southern Oregon, says he never encourages people to use marijuana, but he acknowledges that people are going to use it. He also says, if you are one of them, be careful. Accidentally overdosing is surprisingly easy. Vogel spoke to about 30 EOU students, and said marijuana users are most likely to overdose while eating foods containing it instead of smoking it. The psychoactive effect of marijuana is not felt until 90 to 120 minutes after it is eaten, and he said a marijuana overdose is a nightmarish psychological experience.