Mai Ya (Barley Sprout, Malt)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Mai Ya, and how does dose change its effect on lactation?

  For ordinary digestive use, roughly 10–15 g in decoction (Chen & Chen) or 9–15 g (Bensky); for its effect on lactation the dose is what matters most — large doses (roughly 30–120 g per Chen & Chen, or 30–60 g per Bensky) are traditionally used to reduce or stop lactation and breast distension, while small doses are said to instead promote milk flow. Sources are consistent that direction of effect on lactation tracks dose size, not a different preparation of the herb.

  Source: Sacred Lotus sources & references (Bensky and Chen & Chen dosage ranges as recorded on file). Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Mai Ya, especially for nursing mothers?

  Large doses of Mai Ya should not be used by mothers who wish to continue nursing, since this is the traditional dose range said to reduce or stop lactation — this is a genuine, dose-dependent caution rather than a blanket contraindication, since small doses are traditionally considered supportive of milk flow. Mai Ya is also not indicated where there is no food stagnation to begin with.

  • Nursing mothers — avoid large/high doses if continued lactation is desired; discuss dosing with a qualified practitioner.
  • No food stagnation present — not indicated as a general-purpose digestive in the absence of stagnation.

  Source: Sacred Lotus sources & references; cross-referenced against multiple online sources.

Chinese Herb Toxicity & Overdose

• None Noted

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Mai Ya (Hordeum vulgare) and its effect on lactation/prolactin?

  Yes — a 2022 study provides a plausible pharmacological mechanism for Mai Ya's traditional anti-lactation/prolactin-lowering reputation, though it did not test the dose-dependent (promote-at-low-dose, inhibit-at-high-dose) effect directly. Researchers studied “total barley Maiya alkaloids” (TBMA) and the specific alkaloid hordenine — extracted from processed, sprouted Hordeum vulgare, i.e. Mai Ya — in schizophrenia patients on the antipsychotic risperidone (a drug known to raise prolactin), in rats, and in a prolactin-secreting (MMQ) pituitary cell line.

  • Mechanism identified — risperidone-induced prolactin elevation was linked to increased methylation of the dopamine D2 receptor (DRD2) gene promoter; TBMA and hordenine inhibited the DNA methyltransferases responsible, restoring DRD2 expression and lowering prolactin in the treated groups (PMID 35865960, Frontiers in Pharmacology, 2022).
  • Traditional-use confirmation — the paper explicitly describes Maiya as “a common Chinese herbal drug used in the clinic” for treating abnormal lactation, corroborating the traditional indication from a modern research angle.

  Note: this study demonstrates a prolactin-lowering mechanism at the (relatively concentrated, extracted) doses tested; it does not directly test or confirm the classical claim that small decoction doses promote lactation while only large doses inhibit it. That dose-response distinction remains a traditional clinical observation, not yet directly studied.

  Sources: PMID 35865960 (Front Pharmacol, 2022). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Mai Ya different from Gu Ya, and what formulas is it in?

  Mai Ya (germinated barley) and Gu Ya (germinated rice, Oryza sativa) are both sprouted-grain digestive herbs, but Mai Ya is the stronger of the two and is the one associated with the Liver-qi-smoothing and lactation effects — Gu Ya is milder, more purely a Spleen/Stomach digestive aid, and does not carry the same traditional lactation caution. Mai Ya enters the Liver, Spleen, and Stomach channels, while Gu Ya is recorded as entering only Spleen and Stomach; in practice Gu Ya is often preferred for weaker patients (children, the elderly, or convalescents) needing a gentler appetite-and-digestion herb, while Mai Ya is reached for when Liver-qi constraint or a need to reduce lactation is also part of the picture.

  • Jian Pi Wan (Strengthen the Spleen Pill) — a Spleen-qi-tonifying, food-stagnation-reducing formula.
  • Zhi Shi Xiao Pi Wan (Immature Bitter Orange Pill to Reduce Focal Distension) — combines Mai Ya with Zhi Shi and Spleen-strengthening herbs for focal distension with underlying deficiency.
  • Fei Er Wan (Fat Baby Pill) — a pediatric formula for food stagnation and poor growth.
  • Zhen Gan Xi Feng Tang (Sedate the Liver and Extinguish Wind Decoction) — here Mai Ya's mild Liver-qi-smoothing action helps offset the heavy, potentially Stomach-taxing minerals in the formula. (Traditional formula context, not treatment advice.)

  Source: Sacred Lotus sources & references (Gu Ya/Mai Ya channel comparison, formula links); cross-referenced against multiple online sources.