This study evaluated the toxicity of RedBull, caffeine, sucrose, and taurine. The analysis, done at the Karlsruhe Institute of Technology on Zebrafish larvae and PAC 2 cells, tested a range of concentrations of the substances. At 24h exposure, live cells observed in 100% RedBull showed major change in shape. Cells seemed unaffected in 50% Red Bull but dying in 10% RedBull. DAPI DNA quantification and Trypan blue staining confirmed that the 10% RedBull cells were dead, the ones in higher concentrations were alive yet showed compromised cell division and membrane structure. Zebrafish larvae growth was affected by high concentration of all substances and 500 µM Caffeine increased their photo motor response. Our results showed that RedBull low concentration is toxic for cells and organisms.