Phellostatin combines the Four Gentlemen Decoction (Si Jun Zi Tang) as a digestive tonic with herbs shown to have anti-fungal action. There are many active constituents in Phellostatin, providing a broad-based anti-fungal therapy. Varied active components lessen the chance that resistant strains of fungi may arise. Phellodendron (huang bai) is widely used in China for intestinal infections. Plantago (che qian zi) and cnidium seed (she chuang zi), houttuynia (yu xing cao), pulsatilla (bai tou weng) are the strongest anti-fungal herbs in the formula. Cardamon (sha ren) treats flatulence.