Fructus Tritici Levis — the light, shrivelled, unripe caryopsis of Triticum aestivum L. (family Poaceae), separated by flotation because it floats while sound grain sinks.
Nature and flavour. Sweet, cool. Heart system.
The mildest entry in the entire astringent class, because it is a food. The sources record it for spontaneous sweating and for night sweating, for the low fever and vague heat that the texts describe as deficiency heat, and for the exhaustion that follows prolonged illness. It is a staple of the classical sweat-arresting combinations and it is also simply what a household had to hand. Its traditional reputation for arresting sweating rests on classical authority rather than on controlled evidence; the clinical claims are not established, and the honest reading of the sources is that this is a gentle traditional remedy whose strongest support is long use and an unusually good safety record, not trial data.
性味归经。甘，凉。归心经。
收涩药里最平和的一味，因为它本来就是粮食。文献记载其用于自汗、盗汗，以及古籍所称虚热所致的低热、烦热，还有久病之后的气短乏力。它是古典止汗组合里的常客，也是寻常人家手边就有的东西。其「止汗」的传统声誉来自古典文献权威而非对照研究；临床说法尚未被证实。对文献诚实的读法是：这是一味温和的传统用药，最有力的支持是长期使用史与相当好的安全记录，而不是试验数据。
含麸质。这是硬边界：乳糜泻与小麦过敏者完全不宜，它也不能替代需要无麸质饮食者的饮食管理。「止汗」的传统声誉没有对照证据支持。更要紧的是：出汗与盗汗本身不是诊断。它们可见于甲状腺功能亢进、结核、淋巴瘤等肿瘤、使用胰岛素或磺脲类者的低血糖、绝经期、某些抗抑郁药以及急性感染；盗汗伴体重下降或发热应当去检查，而不是喝小麦浸液。婴幼儿、孕期与哺乳期，证据根本不存在。受潮储存的麦粒可能霉变；这是食品级材料，应按食品对待。