Tripterygium wilfordii, or lei gong teng, sometimes called Thunder God Vine, is a vine used in traditional Chinese medicine for treatment of fever, chills, edema and carbuncle.It is also under investigation for its apparent antifertility effects, which it is speculated, may provide a basis for a Male oral contraceptive. Tripterygium wilfordii recently has been investigated as a treatment for a variety of disorders including rheumatoid arthritis, chronic hepatitis, chronic nephritis, ankylosing spondylitis, as well as several skin disorders. A refined extract from the root xylem of Tripterygium wilfordii Hook. f. (the so-called multi-glycosides of the plant), available in the market as tablets for the long-term treatment of rheumatoid arthritis and various skin disorders, has recently been shown to possess a powerful antifertility effect in male rats and in men after oral administration at dose levels not showing apparent toxicity or side effects.