Seven relations

Seven relationships or interactions of medicinals, namely: going alone; mutual need; empowering; fear; aversion; killing; clashing.

Going alone (单行 dān xíng) (单行 dān xíng): The ability of a medicinal to be used alone, as in Licorice Decoction (甘草汤 gān cǎo tāng) and Pure Ginseng Decoction (独参汤 dú shēn tāng).

Mutual need (相虚 xiāng xū) (相须 xiāng xū): Also called mutual enhancement. The combined use of two medicinals of similar action used together to enhance each other’s action. The implication is that the combined use of the two medicinals is greater than the sum of their individual action. Mutual need medicinals include anemarrhena (Anemarrhenae Rhizoma, 知母 zhī mǔ) and phellodendron (Phellodendri Cortex, 黄柏 huáng bǎi).

Empowering (相使 xiāng shǐ) (相使 xiāng shǐ): The use of one or more agents to enhance the action of a main agent. For example, apricot kernel (Armeniacae Semen, 杏仁 xìng rén) empowers coltsfoot (Farfarae Flos, 款冬花 kuǎn dōng huā) to moisten the lung and downbear qì, and to relieve cough and transform phlegm.

Fear (相畏 xiāng wèi) (相畏 xiāng wèi): Toxicity of a medicinal being counteracted by another. For example, pinellia (Pinelliae Rhizoma, 半夏 bàn xià) fears fresh ginger (Zingiberis Rhizoma Recens, 生姜 shēng jiāng) because its toxicity is reduced by it. Astragalus (Astragali Radix, 黄芪 huáng qí) was traditionally said to fear saposhnikovia (Saposhnikoviae Radix, 防风 fáng fēng), although in Jade Wind-Barrier Powder (玉屏风散 yù píng fēng sǎn) astragalus (Astragali Radix, 黄芪 huáng qí) is said to be empowered by saposhnikovia (Saposhnikoviae Radix, 防风 fáng fēng). NB: The Chinese 畏 wèi means fear, but in this context implies that negative effects only are threatened.

Aversion (相恶 xiāng wù) (相恶 xiāng wù): The weakening of the effectiveness of one medicinal by another medicinal. For example scutellaria (Scutellariae Radix, 黄芩 huáng qín) is averse to fresh ginger (Zingiberis Rhizoma Recens, 生姜 shēng jiāng) because its action is weakened by it; ginseng (Ginseng Radix, 人参 rén shēn) is averse to radish (Raphani Radix, 莱菔 lái fú), since its supplementing action is reduced by it. NB: The Chinese 恶 wù implies dislike, sickening, ailing, hence weakening; see nausea.

Killing (相杀 xiāng shā) (相杀 xiāng shā): The elimination of side effects of a medicinal. For example, mung bean (Phaseoli Radiati Semen, 绿豆 lǜ dòu) kills croton (Crotonis Fructus, 巴豆 bā dòu), i.e., it eliminates the croton’s noxious effects. Note that the Chinese 杀 shā has connotations of purification as well as slaughter.

Clashing (相反 xiāng fǎn) (相反 xiāng fǎn:) The creation of noxious effects when two medicinals are used together. For example, aconite main tuber (Aconiti Radix, 川乌头 chuān wū tóu) clashes with pinellia (Pinelliae Rhizoma, 半夏 bàn xià), so the two should not be used together.

Etymology

Chin 七 qī, seven; 情 qíng, affinity, affection, emotion; fact. The Chinese term qī qíng is identical with the term rendered in other contexts as seven affects. The Chinese names of six of the seven relations contain the character 相 xiāng, usually rendered as mutual or reciprocal; however only in two of the terms, 相须 xiāng xū, mutual need, and 相反 xiāng fǎn, clashing, is any reciprocity implied. The technical meaning of the terms denoting the seven relations is poorly reflected in social metaphor used to describe it.