Chenopodium ambrosioides - American Wormseed
"This agent has long been used as a remedy for worms but because of an early objection made to its use on the grounds of certain subtle, dangerous properties, it has not come into general use. In sufficient doses of from ten to twenty minims of this oil, it was recommended to expel the round worm. Our own authorities seldom recommended above five minims which was not always sufficient though safer.
A recent report puts this agent in its exact place as an anthelmintic. In the Orient, especially in Singapore and in Sumatra, the oil of chenopodium is extensively employed against hookworm and other intestinal parasites. More than 100,000 cases of hookworm of both the Old and New World types have been treated with practically no untoward effects, and with greater success than with any remedy heretofore employed.
In Sumatra, it is used also with equal confidence, in the treatment of roundworm, tapeworm, and whipworm. Weiss of Kisaran treated 5,000 cases of hookworm with highly satisfactory results. There was one case of nephritis which he thought might have followed it, but the case was quickly controlled. Schuffner and Baermann in Sumatra have treated over 40,000 cases without after effects, and with results superior to those obtained from thymol. They Conclude that the efficiency of this remedy over thymol is as 91 to 83."
(Finley Ellingwood: The American Materia Medica, Therapeutics and Pharmacognosy, 1915)