Tripterygium is a climbing vine with a long history of use in traditional Chinese herbal medicine. It is used in mixtures intended for the treatment of arthritis, muscle injury, skin diseases, and other problems. The roots, leaves, and flowers are the parts used medicinally.

Tripterygium is thought to be toxic or even fatal if taken to excess. Extracts made with ethyl acetate or chorloroform-methanol came into use in China in the 1970s, and were said to be less toxic. However, the safety of these extracts has not been conclusively established, and we recommend against using tripterygium except in the context of a scientific trial.

In animal, test-tube, and preliminary human trials, trypterygium has shown immunosuppressive and anti-inflammatory affects.1-7 Because drugs with these properties are useful for conditions in which the immune system is overactive, such as rheumatoid arthritis and lupus, trypterygium has been proposed for similar use. However, as yet there is only minimal evidence that it is effective.

One double-blind, placebo-controlled study performed in China in 1997 evaluated the topical use of a tripterygium extract in 61 people with rheumatoid arthritis.8 The extract was applied 5-6 times daily to the affected joints. The results appeared to indicate that use of the herbal tincture over 6 weeks significantly reduced rheumatoid arthritis symptoms as compared to placebo. However, due to problems in the study, researchers were compelled to use statistical methods that were somewhat questionable (technically, post-hoc analysis). For this reason, the results are only somewhat meaningful.

Another study compared placebo to oral trypterygium extract, taken in a low or high dose for 20 weeks.9 The results appeared to show benefit, but so many participants dropped out before the end of the study that the results are difficult to interpret.

No other potential uses of tripterygium have undergone meaningful controlled clinical trials. Weak evidence hints that it might offer promise as a contraceptive for men.10