Digu Pi Yin (Cortex Lycii Drink) for Lowering Blood Sugar and Relieving Thirst

In the Shengji Zonglu there is a formula usable for type 2 diabetes called “Digu Pi Yin” (Cortex Lycii Drink), composed of: Cortex Lycii (filed), Wanggua root (Trichosanthes cucumeroides root, filed), Tianhuafen (Trichosanthes root, filed), Phragmitis Rhizoma (Lugen, filed), and Ophiopogon (heart removed, dried), each 2 liang (60 g), with 7 jujubes (seed removed). File the herbs into a coarse powder; take 4 qian (12 g) each time with one cup (150 ml) of water, decoct to eight-tenths (120 ml), strain, and take warm at any time. Nowadays the herbs may be ground together in a household blender and the powder decocted as a powder-form decoction.

This formula clears heat and generates fluids; it is indicated for xiaoke (wasting-thirst), with incessant drinking of water day and night and profuse urination. Xiaoke here is what we today call diabetes—patients are thirsty, drink constantly, and urinate abundantly, hence the name. Modern pharmacological research shows that Wanggua root, Tianhuafen, Ophiopogon, Cortex Lycii, and Phragmitis root all have some blood-sugar-lowering effect; in TCM these are all thirst-relieving, fluid-generating herbs, and jujube protects the stomach. Combined, they both treat diabetes symptomatically and lower the patient’s blood sugar.

However, diabetes treatment requires long-term persistence, and taking a decoction for a long time is inconvenient. If one wishes to use this formula for diabetes, it may be made into pills at the above dosage, 10 g each time, twice daily. During treatment, blood sugar should be monitored closely; in some patients blood sugar may not come down with this formula alone, and for them it can only serve as adjunctive therapy—when insulin is needed, insulin must still be used.