Warning: This formula can be toxic to the kidneys because of the herb mu tong. There are different varieties of mu tong in the market. Before the Qing dynasty, however, it was not toxic because mu tong was derived from either the plant of Akebia guinata or the plant Akebia lobata.  Today, ninety five percent of mu tong  used in China is from the stem of Aristolochia debilis, called guan mu tong (關木通), a toxic plant usually grown in the northeastern provinces of China, formally called Manchuria. Only rarely in a few localities in China, is mu tong obtained from Akebia guinata or Akebia lobata being used. Many cases of kidney failure have been reported in  China from taking this formula.Today in China, all manufactured formulae that contain guan mu tong (aristolochia debilis) are being banned because of the toxicity to the kidneys.

If you use this formula, make sure you are not using guan mu tong. Use chuan chuan mu tong or huai tong, or bai mu tong tong instead.