1.2% of individuals in the US, age 13–34, reported use of a novel psychoactive substance.
Use of tryptamines was most common, followed by psychedelic phenethylamines.
Use increased from 2009 through 2013 and use of other illicit drugs was common.
Males, whites and older or unmarried subjects were more likely to report use.
An adaptable survey tool would improve reporting as new drugs continue to emerge.