A classical gynecological formula used to nourish Yin and cool internal Heat, primarily for women whose periods come early but with scanty flow, often accompanied by feeling warm in the palms and soles, night sweats, and a dry throat. It works by replenishing the body's cooling, moistening resources so that excessive internal warmth subsides naturally.

Liang Di Tang addresses a pattern where the Kidneys' Yin (the body's deep reserves of cooling, moistening fluids) has become depleted, allowing internal deficiency Heat to flare up unchecked. In TCM, the Kidneys store the body's foundational Yin and Yang. When Kidney Yin runs low — from overwork, chronic illness, constitutional weakness, or aging — there is no longer enough "Water" to keep "Fire" in balance. This generates a type of smoldering, deficiency Heat (as opposed to a strong, acute fever) that disturbs the blood and disrupts the menstrual cycle.

This internal Heat drives blood to move recklessly, causing the period to arrive ahead of schedule. However, because the root problem is depletion rather than excess, the menstrual flow is scant — perhaps just a drop or two — with a red color and thick, sticky quality. The original text specifically cautions against mistaking this for simple Blood Heat: the key insight is that the Fire is secondary to the Water deficiency. Accompanying signs like tidal flushing, night sweats, dry throat, a red tongue with little coating, and a thin rapid pulse all reflect this Yin-deficient Heat pattern.

The treatment principle follows the classical strategy of "strengthening Water to control Fire" (壮水之主以制阳光, zhuang shui zhi zhu yi zhi yang guang). Rather than directly attacking the Heat with bitter cold herbs (which could further damage Yin), the formula focuses on replenishing the depleted Kidney Yin while gently clearing the resulting deficiency Heat. Once sufficient Yin fluids are restored, the Heat naturally subsides and the menstrual cycle self-corrects.