Complex sentence: None of the non-lethal doses or lethal doses is known, suggesting that the safety gap between a lethal and non-lethal dose of methedrone is probably very small, thus making use of this drug dangerous because poisonings, and simultaneously death, are accidental.
Split into simpler sentences: None of the non-lethal doses or lethal doses is known, suggesting that the safety gap between a lethal and non-lethal dose of methedrone is probably very small. Thus making use of this drug dangerous because poisonings, and simultaneously death, are accidental.