Abstract Toxogonin, administered orally in an aqueous solution to healthy male volunteers, produced dose-related blood levels of oxime. These levels were lower than those found with similar doses of 2-pyridinium aldoxime methochloride. A dose-independent symptom complex of facial warmth and/or numbness and a cool menthol sensation in the throat was similar to, but of less intensity than, that previously seen when toxogonin was given intramuscularly. If toxogonin shows further therapeutic promise, additional investigations into methods to facilitate its gastrointestinal absorption are indicated.