There does not appear to be any scientific evidence supporting the claim that wormwood tea can treat parasitic infections. NYU Langone Medical Center admits there are extremely preliminary indications that wormwood oil may effectively treat parasites, but this is not in tea form and more studies must be performed to find the evidence conclusive. Wormwood consumed in any form is potentially toxic to the nervous system.
The use of wormwood tea to treat intestinal parasites became popular as a result of public figures such as Dr. Oz recommending the remedy to viewers and readers. He states on his website that there are studies available suggesting that wormwood tea may paralyze or kill certain parasites, but he does not cite his sources. This information is misleading. According to NYU Langone Medical Center, wormwood has been said to treat other digestive conditions, such as dyspepsia, esophageal reflux and irritable bowel syndrome, but there is no meaningful evidence to indicate that it is effective for any of these conditions. A 2007 study conducted in Germany raised hopes that the wormwood-containing herbal blend the subjects were given might relieve symptoms of Crohn's disease, but further research is necessary to establish wormwood as a helpful treatment.