Lobelia frequently causes nausea and vomiting when the amount used is too high. Generally, more than 1 ml of tincture or acetract taken at one time will cause nausea and possibly vomiting and should be avoided.¹² Although lobelia has a reputation for being toxic, a thorough review of the medical literature was unable to find any well-documented case of serious problems or death due to lobelia.¹³ This may be because a toxic amount cannot be ingested without first causing vomiting. Signs of lobelia poisoning may include weakness, heartburn, weak pulse, difficulty breathing, and collapse.¹⁴ Nevertheless, lobelia should not be used for more than one month consecutively and should be avoided during pregnancy and breast-feeding.¹⁵ Due to its emetic (vomit-inducing) actions, lobelia should be used cautiously with children under the age of six years.