IntroductionThe recreational use of psilocybin or psilocin-containing products, a chemical found naturally in certain mushroom species, is on the rise across the United States. Several cases of serious clinical effects related to mushroom-containing products have recently been reported to the Food and Drug Administration (FDA). The emergence of these new products and their health consequences are not yet well understood. This case series aims to characterize exposures to mushroom-containing chocolate products, including patient characteristics, clinical effects, treatment(s), and clinical outcome severity, reported to a poison center network. Material and methodsThis was a retrospective case series conducted in patients exposed to mushroom-containing chocolate products across three poison centers between January 2023 to August 2024. Patients were identified via a database search of ToxSentry®. Patients were included if they were exposed to a mushroom-containing chocolate product. Patients were excluded if they ingested an unrelated product or if there was insufficient information documented within ToxSentry®. The primary endpoint was to describe clinical outcome severity after exposure to mushroom-containing chocolate products. ResultsA query of ToxSentry® identified 164 cases; 36 cases met study criteria. The median age of patients in this case series was 17 years old. For most patients (23, 64 %), the reason for the exposure was intentional, with 20 reporting intentional abuse or misuse of the product. Common clinical effects reported included mental status changes (26, 76 %), paranoia/hallucinations (10, 28 %), dysrhythmias (7, 19 %) and gastrointestinal discomfort (6, 17 %). There was one report of seizure. Most clinical effects lasted between 3 and 24 h after ingestion (29, 81 %). Intravenous fluids (18, 50 %) and benzodiazepines (7, 19 %) were the most common treatments given. No fatalities were reported. DiscussionWhile most patients in this series experienced minor clinical effects, some developed serious effects after ingestion of a mushroom-containing chocolate product. Findings from this study further characterize the limited patient demographics, clinical effects, and outcomes published thus far. Further characterization in a larger cohort of patients could expand on our initial findings and is needed to better identify factors that may influence clinical outcomes.