In Traditional Chinese Medicine (TCM), Xu Duan belongs to the 'Tonic herbs for Yang Deficiency' category. Tonic herbs are used for patterns of Deficiency, when one lacks one of the 'Four Treasures' (Qi, Blood, Yin and Yang). Yang Tonics are generally used in combination with a small amount of Yin tonics. If Yin is deficient, neither Qi nor Yang herbs alone will be effective. The most common symptoms associated with Yang Deficiency are low libido and impotence. It is worth mentioning that another very effective remedy against Yang Deficiency is regular exercise.

Furthermore Xu Duan is Warm in nature. This means that Xu Duan tends to help people who have too much 'Cold' in their body, although with less effect than a plant that would be Hot in nature. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Cold in their body are said to either have a Yin Excess (because Yin is Cold in nature) or a Yang Deficiency (Yang is Hot in Nature). Depending on your condition Xu Duan can help restore a harmonious balance between Yin and Yang.

Xu Duan also tastes Bitter and Sour. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Bitter ingredients like Xu Duan tends to have a cleansing action on the body by clearing Heat, drying Dampness and promoting elimination via urination or bowel movements. On the other hand Sour ingredients help with digestion and restrain abnormal discharges of Fluids from the body, such as diarrhea or heavy sweating.

The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such Xu Duan is thought to target the Kidney and the Liver. According to TCM, the Kidneys do not only regulate the urinary system but also play a key role in the reproductive system and the growth and aging process of the body. The Liver on the other hand is often referred as the body's "general" because it is in charge of regulating the movements of Qi and the Body Fluids. It also takes a leading role in balancing our emotions.