What Er Zhi Wan is for
The name refers to the two solstices, and the skin picture suits that timescale: dryness that has settled in slowly, where the surface has thinned and lost its spring rather than flaring and reddening. Two herbs, both mild and both taken for months rather than days, make it a base for the long rebuild rather than a treatment for an active flare.
The skin is dry in a fine, even way, thin and less elastic, so it creases early and holds the crease. There is no redness and no scaling edge: the surface looks underfed rather than inflamed, with a dull, faintly papery finish and a tendency to fine flaking. Hair thins and greys within the same picture, and the scalp flakes dryly rather than greasily.
Nu Zhen Zi restores Liver and Kidney Yin, the reserve that keeps skin supple and hair nourished, and Mo Han Lian, also called Han Lian Cao, nourishes Yin and cools the Blood so that mild deficiency heat does not dry the surface further. Both are mild and non-greasy, which is why the pair can be taken for months without burdening the digestion, and why it is often used as a base to which other herbs are added.
It suits the slow, age-related picture and not an active flare: weeks to months, not days. It is wrong for cold, pale skin with cold limbs, and for cold digestion with loose stools, because both herbs are cool and moistening. It is also too gentle on its own once the dryness has progressed to cracking, where a stronger Yin tonic is needed.
Actions
- Nourishes Liver and Kidney Yin
- Moistens dryness
- Cools the Blood gently
- Supports hair and eyes
Properties
- Taste and temperature: Predominantly sweet and cool with a mild bitter note. Sweet and moistening to nourish Yin, cool to clear mild deficiency heat.
- Organs: Liver, Kidney
- Channels: Liver, Kidney
The pattern behind it
The root is Liver and Kidney Yin deficiency. Yin moistens and cools, so when it is low the skin and hair lose their suppleness and a mild heat appears. The two herbs restore that reserve gently, which is why the formula is used as a long-term base rather than for acute problems.
Composition
The herbs in Er Zhi Wan, with their role and dose.
| Role | Herb | Dose | Properties | Why it is there |
|---|---|---|---|---|
| Nu Zhen Zi | 9 to 15 g | Cool, Sweet, bitter | Nourishes Liver and Kidney Yin and brightens the eyes, addressing the dryness and the visual symptoms. | |
| Mo Han Lian | 9 to 15 g | Cold, Sweet, sour | Nourishes Yin and cools the Blood, supporting the hair and skin and settling mild deficiency heat. |
Patterns it treats
Yin Deficiency
Dry, thin, inelastic skin that creases early and flakes finely, with thinning hair and a dull rather than inflamed surface. The Yin that keeps the skin supple has declined, so the tissue looks underfed and the dryness is settled rather than eruptive.
How the formula is built
Two mild Yin tonics that complement each other: one leans toward the Liver, the eyes and the hair, the other toward cooling the Blood. Both are non-greasy, so the pair can be taken long term without congesting the digestion, which is why it is often used as a base to which other herbs are added.
Skin conditions it is used for
Where this formula appears in the skin conditions of the library.
Preparation and use
Taken as prepared pills, two to three times a day.
Modifications
- If heat signs are marked, the cooling version Zhi Bai Di Huang Wan is used instead.
- If the Blood is also deficient, Dang Gui and Shu Di Huang are added.
- If the eyes dominate, eye-nourishing herbs are added.
- If the digestion is weak, the pills are taken after food.
Timing
Taken two to three times a day, with or after food.
Duration
Four to twelve weeks as a course, then reassessed, and longer for chronic Yin deficiency under guidance.
Diet while taking it
Avoid drying food such as alcohol, fried food and heavy spice; moistening food supports the treatment.
Safety
Contraindications
Caution in Spleen and Stomach deficiency-cold with loose stools or diarrhoea, since both herbs are cool and moistening. Avoid in Yang deficiency with cold limbs.
Interactions
No major interaction is recorded in the reference beyond the general caution of cool moistening herbs in weak digestion.
Pregnancy
Generally considered safe in pregnancy under professional guidance, as neither herb is contraindicated.
Breastfeeding
Considered acceptable under professional guidance.
Children
Used only with professional supervision.
Before you use it
Recorded from the classical record and rewritten in this project's own words. Educational only: not a prescription.
General safety references
General references for herbal hepatotoxicity and herb-drug interactions; they are not specific to this formula.
- Review article: Herbal hepatotoxicity - an update on traditional Chinese medicine preparations. Alimentary Pharmacology & Therapeutics, 2014. PMID: 24844799.
- Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs, 2009. PMID: 19719333.
- Warfarin and food, herbal or dietary supplement interactions: a systematic review. British Journal of Clinical Pharmacology, 2021. PMID: 32478963.
Origin and history
Yi Fang Ji Jie (医方集解, Medical Formulas Collected and Analyzed) by Wang Ang, Qing dynasty, 1682.
The formula is recorded by Wang Ang in the 17th century as a simple pair for Liver and Kidney Yin deficiency. Its two herbs, named after the solstices, reflect the idea of working on the body's deepest seasonal turning points, and the pair became a standard gentle base for age-related dryness.
Classical record
Wang Ang records the two herbs together as a gentle formula for nourishing Liver and Kidney Yin, used for dryness of the eyes, hair and skin with depletion.
Yi Fang Ji Jie (医方集解, Medical Formulas Collected and Analyzed), Wang Ang, Qing dynasty, 1682.
Evidence note
No controlled trial of this treatment in skin conditions was identified for this entry. What is described here rests on the classical and later materia medica record and on traditional clinical use, not on controlled trial evidence, and it is not a prediction of benefit. Where skin-specific research does exist it is linked above.
Common questions
Why only two herbs?
Because it is designed as a gentle base. Both are mild and non-greasy, so they can be taken for months and combined with other formulas.
Can it help dry skin and hair?
For the dry, depleted, age-related picture, yes over weeks. It is not a treatment for active inflammation.
Who should avoid it?
People with cold digestion and loose stools, or with Yang deficiency and cold limbs, because the herbs are cool and moistening.
How long before results?
Weeks to months, because Yin is slow to rebuild.