Tripterygium wilfordii

Origin: Root of a vine-like plant from Asia.

Dosage: Extract; up to 60 mg three times a day. 

Claims: Reduces pain and inflammation and treats symptoms of rheumatoid arthritis, lupus and other auto­immune diseases.

What we know: Used in Chinese medicine for years, thunder god vine shows evidence of suppressing the immune system.

Studies: A 2006 review of randomized clinical trials shows that thunder god vine improved symptoms of rheumatoid arthritis but serious side effects occurred.

A 2009 study of 121 RA patients conducted in the United States found that those who received 60 mg three times a day of thunder god vine had better response than those who received 1 g twice a day of sulfasalazine. 

And a 2014 Chinese study of 207 RA patients found that those who received 20 mg pills three times a day of thunder god vine did not do worse those receiving 12.5 mg per week of methotrexate. Patients who received both the thunder god vine and the methotrexate had the best response of all. 

This root can cause stomach upset, skin reactions, temporary infertility in men and amenorrhea (lack of menstruation) in women. It should not be used if you are taking immunosuppressive drugs, like prednisone. The leaves and flowers of this plant are highly toxic and can cause death, so preparation should only be made from the root.