Third plateau is a term DXM abusers use to describe a kind of feeling that can occur when they take DXM in doses which far exceed recommended doses. Sometimes these users categorize the high they experience into different “plateaus,” with effects ranging from mild distortions of color and sound to visual hallucinations, dissociative sensations, and loss of motor control. While users describe four plateaus, it is unclear if all users actually experience the same combinations of effects when abusing dextromethorphan.
