There is a growing interest in semi-synthetic cannabinoids, including THC-O-acetate (THC-Oac). Some cannabis marketers and users have claimed that THC-Oac produces psychedelic effects; the current study is the first to examine this claim. Researchers developed an online survey for THC-Oac consumers based on previous cannabis and psychedelic use surveys and in consultation with the moderator of an online forum. The survey assessed the experiential profile of THC-Oac and included items from the Mystical Experience Questionnaire (MEQ), an instrument for assessing psychedelic experiences. Participants reported a low to moderate level of cognitive distortions (altered sense of time, difficulties concentrating, difficulties with short-term memory) and few visuals or hallucinations. Participants’ responses were significantly below the threshold for a complete mystical experience on all four MEQ dimensions. Participants who had used classic (5-HT2A agonist) psychedelics had lower scores on all MEQ dimensions. When asked directly, 79% responded that using THC-Oac is “not at all” or “a little” of a psychedelic experience. Some reports of psychedelic experiences may be due to expectations or contaminants. Those having prior experience with classic psychedelics had lower ratings of mystical experiences.