The Chinese classical name for saliva — jin jin yu ye (golden fluids, jade liquid) — reflects the classical understanding that the mouth’s secretions are the most tangible manifestation of the body’s Yin fluid reserves. When Qi-Yin deficiency develops, the first and most noticeable symptom is often persistent dryness: the mouth is dry even after drinking; the throat feels rough and uncomfortable; the body fatigues easily; the heart feels unsettled and cannot fully rest. Yu Quan San (Jade Spring Powder) takes its name from this classical concept: yu quan (jade spring) was the classical term for the mouth’s moistening fluid; the formula’s mission is to restore and sustain this source. Recorded across multiple classical texts from the Song Dynasty (Ren Zhai Zhi Zhi), Ming Dynasty (Gu Jin Yi Jian), and refined by Qing Dynasty physician Ye Tianshi in Ye Tianshi Shou Ji Mi Fang, it treats xiao ke (wasting-thirst disease, corresponding broadly to diabetes and other dryness-wasting patterns) and Qi-Yin deficiency states. Today it is available as Yu Quan San granules for convenient modern use.

I. Historical Source and Name Explanation

The formula’s name, Yu Quan (Jade Spring), references the ancient designation for mouth fluid as a precious bodily resource. Its earliest appearance may be traced to Song Dynasty medical compilations and was definitively recorded in Ming Dynasty Gu Jin Yi Jian. Qing Dynasty physician Ye Tianshi (1666–1745), one of the foundational Wen Bing theorists, included and refined it in Ye Tianshi Shou Ji Mi Fang, establishing the formula’s core indication as xiao ke (wasting-thirst) from Qi-Yin deficiency.

The formula’s traditional preparation was as a powder (san), wrapped in gauze and boiled — a format that reduces the effective dose and produces a gentler, sustained Yin-supplementing action compared to standard decoctions. Modern granule formulation preserves the formula’s core composition and proportions in a convenient, standardised form.

II. Seven-Herb Composition and Formula Analysis

Core composition: Ge Gen (Pueraria root) · Tian Hua Fen (Trichosanthes root) · Sheng Di Huang (fresh Rehmannia) · Mai Dong (Ophiopogon) · Wu Wei Zi (Schisandra) · Nuo Mi (glutinous rice) · Gan Cao (Licorice root). Modern granule form contains standardised proportions of all seven; traditional powder form used equal proportions.

Chief herb — Ge Gen (Kudzu root): sweet-pungent, cool; enters Lung, Stomach. Raises Yang and generates fluids, clears Heat and relieves muscle-layer. Ge Gen’s primary role in this formula is its fluid-generating from Yang action: it stimulates the Spleen-Stomach’s Qing Yang Qi to ascend, distributing fluid essence upward to the mouth, throat, and sensory orifices. This is not merely a Heat-clearing action — it actively promotes the body’s own fluid generation rather than simply supplementing fluids from outside. Modern research confirms Ge Gen contains puerarin and related isoflavones that improve peripheral insulin sensitivity and microcirculation, supporting its classical use in wasting-thirst conditions.

Deputy herbs — Tian Hua Fen, Sheng Di Huang, and Mai Dong: the formula’s Yin-nourishing and Heat-clearing core:

• Tian Hua Fen (Trichosanthes root) — sweet-slightly bitter, slightly cold; enters Lung, Stomach. Clears Heat and purges Fire, generates fluids and stops thirst. Its sweet-cold moistening nature directly addresses the Lung-Stomach dryness from Heat-consuming fluids. Specifically targets the throat and pharynx, rapidly relieving the burning, dry, rough sensation of fluid-depleted throat tissue.
• Sheng Di Huang (fresh Rehmannia) — sweet-bitter, cold; enters Heart, Liver, Kidney. Nourishes Yin and cools Blood, generates fluids and clears Heat. Sheng Di penetrates to the Kidney-Yin root — filling the constitutional Yin reserve that, when depleted, creates the chronic dryness pattern that cannot be resolved by surface fluid supplementation. Also clears the deficiency-Heat generated by Yin insufficiency (hot palms, night sweats).
• Mai Dong (Ophiopogon) — sweet-slightly cold; enters Lung, Stomach, Heart. Nourishes Yin and generates fluids, clears the Lung and Stomach, calms Heart and relieves restlessness. Mai Dong works across three organs: Lung Yin supplementation (dry cough, throat dryness); Stomach Yin supplementation (hunger without appetite, dry nausea); Heart Yin and Spirit calming (restlessness, insomnia). Its Lung-Stomach-Heart triple action makes it particularly suited to the complex Qi-Yin deficiency pattern this formula addresses.

Assistant herbs — Wu Wei Zi and Nuo Mi:

• Wu Wei Zi (Schisandra) — sour-sweet, warm; enters Lung, Heart, Kidney. Consolidates and astringes, supplements Qi and generates fluids, calms Spirit. Wu Wei Zi’s critical double role: (1) it consolidates the Yin fluid being generated by the other herbs — preventing it from “leaking” outward as excessive urination, sweating, or nocturnal emission; (2) its five-flavour complex (but sour-dominant) nature simultaneously generates fluids through its sour-sweet quality while preventing fluid loss through its astringent quality. One herb that both generates and retains — the formula’s Yin-conservation mechanism.
• Nuo Mi (Glutinous rice) — sweet, warm; enters Spleen, Stomach, Lung. Supplements Middle Jiao Qi, nourishes Stomach and Lung Yin, moderates the formula’s cold-natured herbs. Nuo Mi’s warm-neutral quality buffers the overall formula against excessive cooling, preventing the three cool-to-cold herbs (Tian Hua Fen, Sheng Di, Mai Dong) from damaging Spleen-Yang in sustained use. Also directly nourishes Stomach mucosal tissue and aids drug absorption.

Envoy — Gan Cao: sweet, neutral; harmonises all herbs; supplements Qi and benefits the Middle Jiao; moderates the sour-astringency of Wu Wei Zi and the cold nature of the three main Yin-nourishing herbs; directly supplements the body’s Qi through its sweet-neutral action — complementing the formula’s Qi-Yin dual supplementation approach.

Three-characteristic formula design:
① Nourish Yin and generate fluids from both inside and outside: Sheng Di and Mai Dong nourish deep Yin reserves; Tian Hua Fen and Ge Gen promote surface fluid generation and distribution
② Generate and consolidate simultaneously: the three main herbs generate fluids; Wu Wei Zi astringes and consolidates them against ongoing leakage; one builds the reservoir, the other seals the leaks
③ Supplement Qi alongside Yin: Ge Gen raises Yang Qi; Nuo Mi and Gan Cao supplement Middle Jiao Qi; Wu Wei Zi supplements Qi and generates fluids — never purely supplementing Yin without attending to the Qi deficiency that perpetuates Yin depletion

III. Clinical Applications and Modern Use

Core pattern: Qi-Yin deficiency with internal Heat dryness
Persistent dry mouth and thirst even after drinking; throat dryness and discomfort; fatigue and poor energy; poor appetite or hunger without being able to eat much; hot palms and soles; night sweats; insomnia and restlessness; frequent urination; red tongue with scant coating; thin-rapid pulse.

1. Type 2 diabetes — Qi-Yin deficiency type (adjunctive use): classical xiao ke (wasting-thirst) maps to diabetes’ three excesses (polydipsia, polyphagia, polyuria). Qi-Yin deficiency type presents as dry mouth, thirst, fatigue, poor appetite, weight loss. Yu Quan San is used adjunctively with antidiabetic medication to improve dryness symptoms, reduce oxidative stress, and support mucosal and vascular health. Never self-discontinue antidiabetic medication; Yu Quan San is adjunctive, not curative.

2. Chronic dryness conditions (seasonal and constitutional): autumn-winter seasonal dryness; prolonged air-conditioned environments; chronic throat dryness and pharyngitis (Yin-dryness type); Sjögren’s syndrome oral and pharyngeal manifestations.

3. Post-illness recovery (Qi-Yin depletion phase): after prolonged febrile illness, surgery, or chemotherapy — constitutional Qi-Yin depletion producing fatigue, dry mouth, poor appetite, and general weakness. Yu Quan San’s gentle Qi-Yin dual supplementation supports recovery without the over-supplementation risk of richer tonics.

4. Menopausal syndrome (Yin-deficiency type): hot flushes, night sweats, dry mouth, insomnia, and restlessness — Liver-Kidney Yin depletion in the climacteric. Adjunctive use alongside other menopausal formulas or Western HRT.

5. Chronic atrophic gastritis (Stomach Yin deficiency): dry Stomach ache, hunger without appetite, dry nausea and belching, fatigue — Ge Gen and Mai Dong as the primary Stomach-Yin restoring agents.

6. Chronic pharyngitis (Yin-dryness type): dry, scratchy throat with foreign-body sensation; dry cough with minimal sputum; Yin-deficiency-driven pharyngeal mucosal atrophy.

Common modifications:

• Oral dryness and thirst severe: add Yu Zhu 10g, Sha Shen 12g — amplify Yin-nourishing
• Insomnia and restlessness prominent: add Suan Zao Ren 15g, Bai Zi Ren 12g — nourish Heart-Spirit
• Qi deficiency severe (profound fatigue): add Ren Shen 10g or Huang Qi 15g — amplify Qi supplementation
• Constipation from intestinal dryness: add Xuan Shen 10g, Dang Gui 10g — nourish Yin and moisten intestines
• Diabetes with prominent Blood-Stasis signs: add Dan Shen 15g, Ge Gen increase to 20g — Blood-Stasis resolution

IV. Usage, Dosage, and Safety

Patent granule form: warm water reconstitution; take 2 times daily. Patent forms: Hai Tian Yu Quan San and Nong Ben Fang Yu Quan San.

Contraindications: Spleen-Stomach Cold deficiency (cold aversion, loose stool, cold abdomen, white coating — the formula’s cool-to-cold Yin-supplementing herbs will worsen Cold); Yang deficiency pattern (formula not appropriate); pregnant women (Tian Hua Fen has uterine-stimulating properties; contraindicated in pregnancy); allergy to any component; severe chronic disease — adjunctive use only under specialist guidance; discontinue if exterior illness (fever, cold) develops and resume after recovery.

Critical note for diabetes patients: Yu Quan San is an adjunctive formula — it does not replace antidiabetic medication. Blood glucose monitoring should continue unchanged; report any significant glucose changes to your physician; do not alter prescribed medication dosages based on symptomatic improvement from the formula alone.

Lifestyle and dietary support: avoid spicy, oily, and heat-generating foods; reduce or eliminate alcohol; maintain regular sleep (late nights worsen Yin depletion); adequate hydration (but note that in Qi-Yin deficiency the body cannot use water effectively until Yin is restored — so simply drinking more water is insufficient); foods that support the formula: pear, silver ear, lily bulb, lotus root, yam, honey, black sesame, wolfberry.