Standardization of Psilocybin Dosing in a Natural Product–Based Retreat Setting: A Practical Method for Dose Quantification and Adjustment Across Sessions

Natural variation in psilocybin content across mushroom samples presents a significant challenge to consistent dosing in both research and retreat settings. In this observational report, we describe a pragmatic approach for quantifying psilocybin content in naturally sourced material to ensure more standardized dosing across participants. Eleven individuals participated in a 7-day psilocybin retreat, receiving two doses of psilocybin-containing mushrooms. The psilocybin content was chemically analyzed rather than inferred from weight, revealing large variability across samples. Standardization based on measured psilocybin concentration allowed for dose adjustments, including a planned increase of the second dose to approximately twice the first to compensate for known acute tolerance effects. This method provides a model for responsible natural product use in community or retreat settings and can inform future translational research.