Powdered roots of iboga (Tabernanthe iboga) contain ibogaine, an alkaloid that has been used to treat addictions. We report the case of a 30-year-old woman who died after ingesting a powder labeled as Tabernanthe iboga she had bought online. Analysis of the powder revealed the absence of ibogaine but the presence of toxic alkaloids (ajmaline, yohimbine and reserpine) found in Rauvolfia sp. plant species. An original and specific LC–MS/MS method developed to quantify ajmaline, yohimbine and reserpine showed respective concentrations of 109.1 ng/mL, 98.2 ng/mL and 30.8 ng/mL in blood, and 1528.2 ng/mL, 914.2 ng/mL and 561.2 ng/mL in bile. Moreover, systematic toxicological analyses of biological samples showed the presence of oxazepam at therapeutic concentration and cannabinoids. Death could be attributed to ingestion of a substantial quantity of crushed roots of Rauvolfia in association with concomitant drug withdrawal.