Artemisias are used since millenaries and never any toxic effect was noticed. If there was one it would have been highlighted by Bigparma because the plant competes with their pills.
The WHO guidelines state that, if the herbal product has been traditionally used without demonstrated harm, no specific restrictive action should be undertaken. In this case WHO maintains the position that there is no requirement for pre-clinical toxicity testing. Pre-clinical toxicity testing is only required for new medicinal herbal products which contain herbs of no traditional history of use.