Materia Medica and Herbal Pharmacology
Materia Medica and Herbal Pharmacology
This domain tests properties, flavors, channel tropism, actions, combinations, dosage, processing, and safety of medicinal substances.
Core rules
- Four natures: cold, cool, warm, hot; balanced substances are neutral. Cold clears heat; warm disperses cold.
- Five flavors: pungent disperses/moves, sweet tonifies/harmonizes, sour astringes, bitter drains/dries, salty softens/purges; bland leaches damp.
- Channel tropism predicts where an herb acts; direction (upward/downward, floating/sinking) depends on nature, flavor, processing, and combination.
- Categories include release exterior, clear heat, purge, drain damp, warm interior, regulate qi, invigorate blood, stop bleeding, transform phlegm, calm spirit, and tonify.
- Processing reduces toxicity or changes action. Dose, decoction time, and combination matter: some herbs are added later, some wrapped, some taken with honey.
Worked example
A patient with wind-cold, absence of sweating, and wheezing. Ma Huang (Ephedra) is pungent, warm, releases exterior and calms wheezing; Xing Ren (Apricot seed) descends Lung qi. Together they address the pattern. Reasoning: the chief herb releases contraction, the assistant directs qi downward. Because Ma Huang can raise blood pressure and cause insomnia, screen for hypertension and caution in deficiency sweating.
Traps
Do not select herbs by single symptom. Do not assume natural means safe: toxic herbs require exact dose and processing. Do not ignore pregnancy cautions, incompatibilities, or herb-drug interactions. Flavor is not identical to action.