Patterns Addressed
In TCM, symptoms don't appear randomly — they cluster into recognizable patterns of disharmony that reveal what's out of balance in the body. Yi Gan San is designed to correct these specific patterns.
Why Yi Gan San addresses this pattern
When Liver Blood is insufficient, it fails to anchor Liver Yang and nourish the sinews, allowing internal Wind to stir. This produces spasms, tremors, twitching, teeth grinding, restless sleep, and emotional agitation. Yi Gan San addresses this directly: Gou Teng calms the Wind and clears the Heat that accompanies it, while Dang Gui and Chuan Xiong replenish and move Liver Blood to address the root deficiency. Chai Hu ensures Liver Qi flows smoothly so it does not generate further Heat. The overall effect is to calm Wind at the branch level while nourishing the Blood foundation that prevents its recurrence.
A practitioner would look for one or more of these signs
Involuntary twitching of muscles, eyelids, or limbs
Teeth grinding or jaw clenching, especially during sleep
Convulsions or spasms, particularly in children
Easily angered, nervous temperament
Restless sleep, difficulty settling
Trembling of hands or limbs
Why Yi Gan San addresses this pattern
When the Liver's Qi becomes constrained and excessive, it overacts on the Spleen (Wood overacting on Earth), causing digestive symptoms alongside emotional disturbance. This produces a combination of irritability, sighing, and emotional tension together with nausea, vomiting, bloating, poor appetite, and loose stools. Yi Gan San addresses both sides of this pattern: Chai Hu courses the constrained Liver Qi, while Bai Zhu, Fu Ling, and Gan Cao strengthen and protect the Spleen. Dang Gui and Chuan Xiong nourish Liver Blood to soften the Liver's excessive action, and Gou Teng further calms the hyperactive Liver. This dual strategy of restraining the Liver while supporting the Spleen resolves both the emotional and digestive symptoms.
A practitioner would look for one or more of these signs
Bloating and fullness, especially after eating
Nausea or vomiting of phlegm and food
Reduced desire to eat
Irritability and emotional tension
Difficulty sleeping, restless nights
Why Yi Gan San addresses this pattern
When Liver Fire flares upward, it can generate internal Wind, producing sudden spasms, convulsions, fever, and agitation. In children this often manifests as acute infantile convulsions (急惊风). The Heat component causes fever, flushed face, and irritability, while the Wind component causes the convulsive movements. Yi Gan San is appropriate when this pattern arises from a background of deficiency rather than pure excess. Gou Teng clears the Heat and extinguishes the Wind, Chai Hu disperses the constrained Liver Fire, and the Blood-nourishing herbs prevent the Fire from consuming Liver Blood further. The Spleen-supporting herbs prevent the agitated Liver from disrupting digestion.
A practitioner would look for one or more of these signs
Fever with alternating chills
Convulsions, particularly in children
Night crying or night terrors in children
Pronounced agitation and excitability
Commonly Prescribed For
These conditions can arise from the patterns above. A practitioner would consider Yi Gan San when these conditions are specifically caused by those patterns — not for all cases of these conditions.
TCM Interpretation
In TCM, the behavioral and psychological symptoms seen in dementia are understood through the lens of Liver and Kidney decline combined with Blood and Yin deficiency. As people age, Kidney Essence and Liver Blood naturally diminish. When Liver Blood becomes insufficient, it can no longer anchor Liver Yang, which rises unchecked and generates internal Wind. This produces agitation, hallucinations, shouting, aggressive behavior, and sleep disturbance. The spirit (Shen) loses its rootedness when Blood and Yin are depleted, leading to confusion, anxiety, and emotional volatility. Meanwhile, the weakened Spleen fails to produce adequate Qi and Blood, worsening the overall deficiency cycle.
Why Yi Gan San Helps
Yi Gan San calms Liver Wind and clears Liver Heat through Gou Teng, directly reducing the neurological excitability that drives agitation, hallucinations, and aggression. Chai Hu smooths the flow of Liver Qi, helping to ease emotional volatility. Dang Gui and Chuan Xiong nourish and move Liver Blood, addressing the root deficiency that allows Wind to stir. Bai Zhu, Fu Ling, and Gan Cao support the Spleen to maintain digestive function and adequate nutritional intake. Multiple clinical trials in Japan have shown that Yokukansan (the Japanese preparation of this formula) significantly reduces behavioral symptoms on the Neuropsychiatric Inventory scale, with particular improvements in delusions, hallucinations, and agitation.
TCM Interpretation
Insomnia in this context stems from the spirit (Shen) being unable to settle peacefully because the Liver is disturbed. When Liver Blood is deficient, the spirit lacks a proper residence and becomes restless. When Liver Qi is constrained, it generates Heat that rises and agitates the Heart, where the Shen resides. The person may experience difficulty falling asleep, frequent waking, vivid or disturbing dreams, and a general sense of nervous tension that prevents relaxation. This type of insomnia is often accompanied by irritability, teeth grinding, and a wiry pulse.
Why Yi Gan San Helps
Yi Gan San addresses insomnia by calming the overactive Liver rather than by directly sedating. Gou Teng cools and subdues the rising Liver activity that disturbs the spirit at night. Fu Ling provides an additional spirit-calming effect. Dang Gui nourishes Liver Blood so the spirit has a stable foundation in which to rest. Chai Hu releases the Qi constraint that generates the Heat disturbing sleep. The formula is particularly well suited for insomnia accompanied by nervous tension, irritability, or physical twitching and teeth grinding during sleep.
TCM Interpretation
Anxiety in TCM often involves the Liver failing to maintain the smooth flow of Qi throughout the body. When Liver Qi becomes constrained, the person feels a sense of pent-up tension, irritability, and apprehension. If this constraint generates Heat, it rises to disturb the Heart and spirit, producing palpitations, racing thoughts, and a feeling of being on edge. When the Liver overacts on the Spleen, anxiety is accompanied by digestive symptoms like nausea, abdominal bloating, and appetite changes. The overall picture is one of nervous hypersensitivity with both emotional and physical manifestations.
Why Yi Gan San Helps
Yi Gan San is suited for anxiety that presents with pronounced irritability, nervous excitability, and physical tension. Gou Teng and Chai Hu together calm the Liver and release its constraint, reducing the nervous overstimulation at the core of the condition. Dang Gui and Chuan Xiong nourish and move Blood to soften the Liver, while Bai Zhu, Fu Ling, and Gan Cao strengthen the Spleen to address any concurrent digestive symptoms and to provide a stable foundation for the body's Qi. The formula is especially appropriate for people who are constitutionally sensitive, easily startled, quick to anger, and prone to nervous excitability.
Also commonly used for
Epilepsy and childhood convulsions
Childhood tic disorders and Tourette syndrome
Neurosis and neurasthenia
Bruxism, particularly nocturnal
Menopausal irritability, insomnia, and mood disturbance
Adjunctive use for agitation and hallucinations
Emotional dysregulation and impulsivity
Involuntary repetitive movements
Trembling not due to Parkinson's disease
Childhood night crying and sleep disturbance
What This Formula Does
Every TCM formula has a specific set of actions — here's what Yi Gan San does in the body, explained in both everyday and TCM terms
Therapeutic focus
In practical terms, Yi Gan San is primarily used to support these areas of health:
TCM Actions
In TCM terminology, these are the specific therapeutic actions that Yi Gan San performs to restore balance in the body:
How It Addresses the Root Cause
TCM doesn't just suppress symptoms — it aims to resolve the underlying imbalance. Here's how Yi Gan San works at the root level.
Yi Gan Tang addresses a pattern where the Liver loses its ability to spread Qi smoothly, generating internal Wind and deficiency Heat that disturb both the nervous system and the digestive system. In TCM, the Liver is responsible for the free flow of Qi and for storing Blood. When Liver Blood becomes insufficient, it can no longer anchor and nourish the Liver's Yang aspect. The resulting "deficiency Heat" (虚热) is not a raging fire but a relative excess of Yang caused by the weakened Yin and Blood failing to keep it in check. This unstable Liver generates internal Wind, which manifests as tremors, spasms, convulsions, teeth grinding, eye twitching, and general nervous agitation.
The Liver in its agitated state also attacks the Spleen ("Wood overacting on Earth"), disrupting digestion and causing nausea, phlegm production, abdominal bloating, and poor appetite. Meanwhile, the rising Liver Wind and Heat disturb the Heart and Spirit, leading to irritability, restless sleep, night crying in children, anxiety, and fright. This creates a self-reinforcing cycle: poor digestion weakens Blood production, which further starves the Liver, which generates more Wind and Heat. The formula intervenes at every point in this cycle, calming the Liver, extinguishing Wind, nourishing Blood, and strengthening the Spleen simultaneously.
Formula Properties
Every formula has an inherent temperature, taste, and affinity for specific organs — these properties determine how it interacts with the body
Overall Temperature
Taste Profile
Predominantly bitter and sweet with mild acrid notes. The bitter and acrid qualities (from Chai Hu, Chuan Xiong, and Gou Teng) disperse, move Qi, and clear Heat, while the sweet quality (from Bai Zhu, Fu Ling, Gan Cao, and Dang Gui) tonifies the Spleen and nourishes Blood.
