Platycodon grandiflorus has a bitter and pungent taste, and a slightly warm nature. It is an excellent remedy for phlegm cough and various throat ailments, with its effects mainly manifested in the following five aspects.
Expelling Phlegm and Discharging Purulence Platycodon is an effective medicine for promoting lung qi, expelling phlegm, and draining pus. For treating lung abscess with symptoms like chest pain, fever, coughing up purulent and bloody sputum, and yellowish, foul-smelling phlegm, it is combined with licorice to form the "Platycodon Decoction" (Jie Tang), which yields excellent results. It can also be used with Houttuynia cordata, Coix seed, and reed root.
Opening and Diffusing Lung Qi Platycodon's pungent and dispersing, bitter and draining properties allow it to open and diffuse lung qi, transform phlegm, and widen the chest. It is a key medicine for stopping cough and expelling phlegm, applicable to coughs from both external contraction and internal injury, regardless of whether they are due to cold or heat. For coughs due to wind-cold with white, clear, and thin phlegm, it can be combined with perilla seed and apricot kernel, as in the Apricot-Perilla Powder (Xing San San). For coughs due to wind-heat with yellow, thick phlegm, it is often combined with mulberry leaf, chrysanthemum, and apricot kernel, as in the Mulberry-Chrysanthemum Decoction (Sang Ju Yin).
Benefiting the Throat and Restoring Voice When external pathogens bind the body's surface, and pathogenic qi stagnates in the lungs, causing sore throat, hoarseness, or even aphonia, platycodon can be used. For sore throat and loss of voice caused by wind-heat invading the lungs, it is commonly combined with licorice, mint, and arctium fruit. For severe swelling and pain of the throat caused by toxic heat accumulation, it can be used with blackberry lily, puffball, and isatis root.
Promoting Urination and Bowel Movements By opening and diffusing lung qi, platycodon can help the water passages of the lower jiao and bladder function smoothly. Adding platycodon to formulas like the Five-Ingredient Powder with Poria (Wu Ling San) or Eight-Ingredient Powder for Rectification (Ba Zheng San) enhances its effect of promoting urination. The lung and the large intestine are exteriorly-interiorly related. When the lung fails to descend and clear, it can affect the large intestine's function of transporting and excrement. Adding platycodon to purgatives can aid bowel movements. For instance, if the Major Aconite Decoction (Da Cheng Qi Tang) is not effective for constipation, adding platycodon can achieve satisfactory results.
Acting as a Vehicle for Medicinal Ascension Platycodon has the effect of lifting lung qi, which can guide pathogenic dampness back to its normal pathways. For example, the Ginseng and Poria Powder with Atractylodes and Dioscorea (Shen Ling Bai Zhu San) is used to treat spleen deficiency complicated with dampness. In this formula, platycodon is included to act as a vehicle for the other medicinal ingredients to ascend, diffuse and promote lung qi, thereby also benefiting the lung qi.