Background and Objectives: The popularity of tryptamines such as N,N-dimethyltryptamine (DMT) appears to be increasing in the United States (US), but epidemiologic literature on prevalence of use is scant. This paper aims to determine trends in prevalence and correlates of past-year tryptamine use among a nationally representative sample of young adults in the US. Methods: Participants in the National Survey on Drug Use and Health survey were queried about past-year use of tryptamines—specifically DMT, α-methyltryptamine (AMT), and 5-MeO-DIPT (“Foxy”). Data were examined from young adults (ages 18–25), years 2007–2014 (N = 144,787). Linear trends in prevalence of past-year tryptamine use were examined in the full sample and stratified by specific demographic and drug use characteristics. Results: Tryptamine use is rare, but increased from.2% in 2007/08 to.7% in 2013/14, a 273% relative increase (p <.001). While prevalence increased among all demographic groups, prevalence was substantially higher among individuals who use other drugs. In particular, between 2007/08 and 2013/14, prevalence of tryptamine use increased among past-year ecstasy users (from 2.1% to 10.0%) and LSD users (from 7.0% to 15.5%) (ps <.01). Prevalence of tryptamine use tended to be higher among lifetime and past-year users of psychedelic drugs compared to users of non-psychedelic drugs. Conclusion: While tryptamine use is not prevalent in the general young adult population, prevalence is increasing. Users of various other drugs — particularly drugs with psychedelic effects — report higher prevalence of tryptamine use. Scientific Significance: Users of other drugs can be targeted when disseminating information about tryptamines to ensure user safety.