Laboratory findings suggest that thunder god vine may fight inflammation, suppress the immune system, and have anticancer effects.
Although early evidence is promising, there have been few high-quality studies of thunder god vine in people. Results from a large study funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), which compared an extractextractto get, separate, or isolate a desired active ingredient of thunder god vine root with a conventional medicine (sulfasalazine) for rheumatoid arthritis, found that participants' symptoms (e.g., joint pain and swelling, inflammation) improved more significantly with thunder god vine than with sulfasalazine.
A small study on thunder god vine applied to the skin also found benefits for rheumatoid arthritis symptoms.
There is not enough scientific evidence to assess thunder god vine's use for any other health conditions.
Thunder god vine can cause severe side effects and can be poisonous if it is not carefully extracted from the skinned root. Other parts of the plant – including the leaves, flowers, and skin of the root – are highly poisonous and can cause death.
A number of participants in the NIAMS study experienced gastrointestinal adverse effects such as diarrhea, indigestion, and nausea, as well as upper respiratory tract infections. (The rate of adverse effects was similar in both the thunder god vine and sulfasalazine groups.)
Thunder god vine can also cause hair loss, headache, menstrual changes, and skin rash.
There are no consistent, high-quality thunder god vine products being manufactured in the United States. Preparations of thunder god vine made outside the United States (for example, in China) can sometimes be obtained, but it is not possible to verify whether they are safe and effective.
Thunder god vine has been found to decrease bone mineral density in women who take the herb for 5 years or longer. This side effect may be of particular concern to women who have osteoporosis or are at risk for the condition.
Thunder god vine contains chemicals that might decrease male fertility by changing sperm.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.