Wormwood is likely safe when taken by mouth in the amounts commonly found in food and beverages including bitters and vermouth, as long as these products are thujone-free. Wormwood that contains thujone is possibly unsafe when it is taken by mouth. Thujone can cause seizures, muscle breakdown (rhabdomyolysis), kidney failure, restlessness, difficulty sleeping, nightmares, vomiting, stomach cramps, dizziness, tremors, urine retention, thirst, numbness of arms and legs, paralysis and death.
Not enough is known to rate the safety of using wormwood topically.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Wormwood is likely unsafe when taken by mouth during pregnancy in amounts greater than what is commonly found in food. The concern is the possible thujone content. Thujone might affect the uterus and endanger the pregnancy. It is also best to avoid topical wormwood, since not enough is known about the safety of applying wormwood directly to the skin.
If you are breast-feeding, do not use wormwood until more is known about safety.
Allergy to ragweed and related plants: Wormwood may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies and many others. If you have allergies, be sure to check with your healthcare provider before taking wormwood.
A rare inherited blood condition called porphyria: Thujone present in wormwood oil might increase the body’s production of chemicals called porphyrins. This could make porphyria worse.
Kidney disorders: Taking wormwood oil might cause kidney failure. If you have kidney problems, talk with your healthcare provider before taking wormwood.
Seizure disorders, including epilepsy: Wormwood contains thujone, which can cause seizures. There is concern that wormwood might make seizures more likely in people who are prone to them.