What are most commonly used herbal substances for diabetes in TCM

Condition analysis:
The Chinese language includes two terms for diabetes. The traditional name, Xiao-ke, correlates closely with diabetes in most instances. Xiao-ke syndrome means "wasting and thirsting." The more modern term, Tang-niao-bing, means "sugar urine illness." Reference to diabetes by the traditional term appears in the earliest texts, including the first medical text in Chinese history, Huang Di Nei Jing, or The Yellow Emperor’s Inner Classic.

Diabetes is classically divided into three types: upper, middle, and lower Xiao-ke. Each has characteristic symptoms. The upper type is characterized by excessive thirst, the middle by excessive hunger, and the lower by excessive urination. These types are closely associated with the lungs, stomach, and kidneys, respectively, and all three are associated with Yin deficiency. At some point during the course of their illness, most people with diabetes manifest symptoms of all three types.

According to TCM, Xiao-ke is attributed to three main factors: improper diet (consuming large quantities of sweets, fatty or greasy foods, alcohol, and hot drinks such as hot coffee or tea), emotional disturbances (stress, anxiety, depression,) and a constitutional Yin deficiency (fatigue, weakness, lethargy, pale complexion).7 To the Western ear, TCM diagnoses sound esoteric, even poetic. In the case of a person with diabetes presenting with symptoms of excessive thirst, the diagnosis can be described as kidney Yin deficiency along with lung Yin deficiency and "internal heat that consumes fluids, thus bringing on wasting and thirsting."

Instructions:
Most commonly used herbal substances for diabetes in TCM:
1. Panax ginseng (Korean ginseng), which has a long history of use as a hypoglycemic agent. At least five constituents of this herb have been shown to exert hypoglycemic effects. In one study, treatment with ginseng lowered blood glucose levels and improved mood and psychological performance as compared with placebo. Recommended dosage is 100–200 mg/day.14

2. Momodica charantia (balsam pear), which is dried, powdered, and made into pills. A dosage of 18 g/day has been shown to reduce blood glucose.15

3. Lagenaria siceraria (bottle gourd), given as a decoction or pills. The recommended dose is 3 g/day. This, too, has been shown to reduce blood glucose levels.15

4. Psidium gnajava, taken in the form of fresh leaves or as an infusion and drunk as a tea. The dosage is 9 g/day. It acts to reduce blood glucose levels.15