“Rationale: 5-methoxy-n,n-dimethyltryptamine is a psychotropic substance found in various plant and animal species and is synthetically produced. 5-methoxy-n,n-dimethyltryptamine is used in naturalistic settings for spiritual exploration, recreation, or to address negative affect and mood problems. however, scientific knowledge on the effects of 5-methoxy-n,n-dimethyltryptamine in humans is scarce. objectives: the first objective was to assess the effects of inhalation of vaporized synthetic 5-methoxy-n,n-dimethyltryptamine on neuroendocrine markers. the second objective was to assess effects of the substance on affect and mindfulness. in addition, we assessed whether ratings of subjective measures were associated with changes in stress biomarkers (i.e., cortisol) and immune response (i.e., il-6, crp, il-1β), as well as the acute psychedelic experience. methods: assessments (baseline, immediately post-session, and 7-day follow-up) were made in 11 participants. salivary samples were collected at baseline and post-session and analyzed by high-sensitivity enzyme-linked immunosorbent assay (elisa). results: 5-methoxy-n,n-dimethyltryptamine significantly increased cortisol levels and decreased il-6 concentrations in saliva immediately post-session. these changes were not correlated to ratings of mental health or the psychedelic experience. relative to baseline, ratings of non-judgment significantly increased, and ratings of depression decreased immediately post-session and at follow-up. ratings of anxiety and stress decreased from baseline to 7-day follow-up. participant ratings of the psychedelic experience correlated negatively with ratings of affect and positively with ratings of non-judgment. conclusion: inhalation of vaporized synthetic 5-methoxy-n,n-dimethyltryptamine produced significant changes in inflammatory markers, improved affect, and non-judgment in volunteers. future research should examine the effect of 5-methoxy-n,n-dimethyltryptamineamine with healthy volunteers in a controlled laboratory setting.”