Mu Li San / Oyster Shell Powder

Mu Li San / Oyster Shell Powder

Chinese Name	牡蠣散
Phonetic	Mu Li San
English Name	Oyster Shell Powder
Classification	Astringent formulas
Source	《Formulas from the Imperial Pharmacy》Tai Ping Hui Min He Ji Ju Fang《太平惠民和劑局方》
Combination	Astragali Radix (Huang Qi) 30g, Ephedrae Herba (Ma Huang Gen) 30g, Ostreae Concha (Duan Mu Li calcined) 30g, Tritici Fructus (Xiao Mai) 30g
Method	Grind huang qi, ma huang gen, and duan mu li into a coarse powder. Mix 9g of the powder together with 30g of xiao mai to constitute one dose to be taken as a draft. The formula is prepared as a decoction. It is best to take the decoction warm. (Modern preparation: the dose of huang qi, ma huang gen, and duan mu li could be reduced according to the clinical presentation while maintaining the original ratios. Combine with 30g of xiao mai and decoct the medicinals in water.)
Action	Astringes yin and arrests sweating, boosts qi and consolidates the exterior.
Indication	Mu Li San is indicated for spontaneous sweating or night sweat in those with a deficient constitution. Symptoms include constant spontaneous sweating that is worse at night, palpitations, easy to become frightened, shortness of breath, vexation, and fatigue. The tongue body is pale or light red and the pulse is thready and weak.
Pathogenesis	This pattern is caused by insufficient wei qi and damaged yin fluids. Insecurity of the wei qi and exterior deficiency allow yin fluids to leak and cause spontaneous sweating. Wei qi’s inability to secure the exterior worsens at night. As one falls into sleep, the wei yang descends into the body’s interior leaving the wei qi even more unable to secure the fleshy exterior. The natural abundance of yin during the night exacerbates the imbalance. Excessive sweating depletes the heart yin and causes heart yin deficiency. As a result, the heart yin fails to subdue yang, which results in night sweat. Sweat is the fluid of the heart and excessive sweating consumes heart yin and damages heart qi. Malnourishment of the heart causes palpitations, propensity to be frightened, shortness of breath, vexation, and fatigue. As seen above, Mu Li San treats sweating caused by various pathologies including: spontaneous sweating due to yang deficiency night sweat due to yin deficiency sweating due to deficiency of both qi and yin The source book states that this formula is used to “treat any insufficiency”. A pale tongue body and a thready, weak pulse both indicate qi and yin deficiency. Therefore, the therapeutic principles are to astringe yin and arrest sweating as well as to boost qi and consolidate the exterior.
Application	1. Essential pattern differentiation Mu Li San is a common formula used to treat spontaneous sweating and night sweat caused by insecurity of the wei qi at the exterior due to qi deficiency, complicated with damaged yin fluids and heart yang hyperactivity. This clinical pattern is marked by sweating, palpitations, shortness of breath, pale tongue, thready and weak pulse. 2. Modern applications This formula is often used to treat various sweating problems such as spontaneous sweating and night sweat caused by tuberculosis, autonomic nerve dysfunction, debility after surgery, delivery, diseases caused by exterior qi insecurity due to general deficiency, and hyperactivity of deficient heart yang due to heart yin consumption.