Yin Chiao has been a staple of traditional Chinese herbalists and acupuncturists, and a household name in China, for hundreds of years. It was developed during the Qing Dynasty (1644-1911), and is one of the most valued of all classic Chinese herbal formulas. It is used for imbalances associated with seasonal changes. Planetary Herbals Yin Chiao Classic is manufactured domestically to insure the purity of this time-honored classic. Suggested Use is 1 tablets twice daily between meals. Contact our in-house customer support team if you have any questions.