The best general formula to dispel internal dampness in Chinese medicine, Shen Ling Bai Zhu contains a variety of herbs that are highly recommended for dampness, leading with codonopsis, poria mushroom, and atracylodes. This formula also contains many of the medicinal foods we recommend for dampness including Chen Pi (aged tangerine peel), Chinese pearl barley (also known as Job’s Tears), lotus seeds, and Chinese yam (Shan Yao).
First appearing in the 1078 Song Dynasty imperial formula manual “Prescriptions of the Bureau of Taiping People's Welfare Pharmacy” Shenling Baizhu San was originally indicated for “those with weak and deficient digestion, poor appetite, fatigue, torpor, sleepiness, bloating, loose stools and shortness of breath.” Most importantly, the imperial physicians noted “This formula is well balanced—long term ingestion cultivates qi, nourishes the spirit, improves digestion, freshens the complexion and strengthens upright qi” (upright qi is a concept close to our modern understanding of the immune system). Thus, the strength of Shen Ling Bai Zhu, apart from its proven efficacy detailed below, comes from the fact that it is a well-balanced, food grade formula which can be taken over a long period of time with little to no worries about side effects.
Modern scientific studies have found that Shenling Baizhu San (SLBZS) treats dampness—extra fluid sitting around in the body—by improving elimination and absorption in the GI, reducing edema, draining lymph and promoting diuresis. A 2019 study of 34 post-operative breast cancer patients with lymphedema found that SLBZS was more effective than the biomedical pharmaceutical diosmin at reducing edema and pain. (1b) A 2020 study found that the principle ingredient in SLBZS, Coix seed, significantly reduced edema in a mouse model. (2) A variety of studies including Feng, 2013 and Xie 2008 (3, 4) have also detailed the diuretic effects of poria and alisma radix. Finally, a network pharmacology study of the combination of poria, ginseng, atractylodes and licorice (known as The Four Gentlemen Decoction) found in SLBZS mitigates GI inflammation, enhancing fluid absorption and elimination and improving symptoms of fatigue and tiredness.