Microdosing psychedelics in subperceptual quantities has become an increas-ingly popular trend through anecdotal claims of alleged benefits such as en-hanced awareness, creativity, mood and mental wellbeing (Fadiman & Korb,2019). Although this practice denotes the absence of subjectively detectablealterations in perception and cognition, microdosing LSD has recently beenshown to induce temporal dilation within the suprasecond range during atemporal reproduction task under double-blind, placebo-controlled condi-tions (Yanakieva et al., 2018) . Following a microdosing event organizedby the Psychedelic Society of Netherlands where participants underwenta double-blind placebo self-administration procedure, we investigated thewithin-subjects effects of psychedelic truffles on basic temporal factors in-volved in multisensory integration of audio-visual speech. Following the pro-cedure developed by E. Van der Burg and Goodbourn (2015), we examinedwhether microdosing psychedelics accutely affects rapid temporal recalibra-tion in response to single audiovisual events and quantified the truffles’ active psychedelic alkaloids. We predicted that psychedelics would increase thetemporal resolution of speech events and dilate the perceived distances between audio-visual stimulus onset asynchronies. Microdosing does not seemto affect this faculty as the point of subjective simultaneity remained solelydependent of the previous leading modality. However microdosing does seemto increase the bandwidth of subjective synchrony judgements, thereby expanding the temporal integration window wherein audiovisual event may veperceived as synchronous.