New psychoactive tryptamines may be a public health risk since they intend to mimic the hallucinogenic effects of regulated psychoactive drugs. Few studies describe uses and clinical effects of unregulated new psychoactive tryptamines. This study aims (1) to explore the presence of tryptamines classified as NPS among the substances delivered for analysis to a harm-reduction organization; (2) to describe the substances found in the samples after analysis; and (3) to compare analytical results of regulated vs. non-regulated tryptamines. Samples delivered and analyzed by gas chromatography-mass spectrometry from 2006 to 2015 were included. A descriptive study of results was conducted. From 25,296 samples that were delivered, 436 were tryptamines; from these 232 (53.21%) were non-regulated. The most delivered non-regulated tryptamine was 4-AcO-DMT. A search of the PubMed database in July 2016 revealed that no studies in humans have ever been carried out with 4-AcO-DMT. Unregulated tryptamines likely contained one unadulterated substance (p ≤ 0.001). The number of samples submitted which contained tryptamines increased during the course of the study, with significant differences in client expectations vs. analysis results between the controlled and uncontrolled groups. There is a need for further research in order to prevent the potential health risks associated with their use.