Luo Han Guo 罗汉果 — Chinese Herbal Medicine

Luo Han Guo (罗汉果) At a Glance

• Herb: Luo Han Guo
• Chinese name: 罗汉果 (Luo Han Guo)
• Latin name: Fructus Momordicae Grosvenorii
• Nature: Cold
• Taste: Sweet
• Meridian: Lung
• Category: Resolve Phlegm Heat

Luo Han Guo, the dried fruit of Siraitia grosvenorii, is a cold, intensely sweet herb that clears heat from the Lung, resolves phlegm, and restores the voice. It is prized for conditions of Lung dryness and Lung heat, including dry or productive cough with yellow phlegm, hoarseness, and sore throat. Its action descends to the Large Intestine, where it moistens dryness and facilitates bowel movement.

Actions & Therapeutic Effects

• Clears Lung heat and resolves phlegm
• Stops cough and calms wheezing
• Moistens the Lung and nourishes Lung yin
• Benefits the throat and restores the voice
• Moistens the intestines and unblocks the bowels
• Generates fluids and relieves thirst

Clinical Applications in TCM

• Lung heat or Lung dryness cough — steep 1–2 fruits as tea, or combine with Sang Ye (Folium Mori) and Pi Pa Ye (Folium Eriobotryae)
• Yellow, viscous phlegm — pair with Gua Lou Pi (Pericarpium Trichosanthis) and Zhe Bei Mu (Bulbus Fritillariae Thunbergii)
• Hoarseness or loss of voice from heat — use alone as a prolonged tea infusion; combine with Pang Da Hai (Semen Sterculiae Lychnophorae) for added effect
• Chronic dry sore throat — combine with Xuan Shen (Radix Scrophulariae) and Mai Dong (Radix Ophiopogonis)
• Heat-type constipation or dryness in the Large Intestine — pair with Huo Ma Ren (Cannabis Semen) and Yu Li Ren (Semen Pruni)
• Thirst and fluid damage from febrile disease — use as tea or combine with Lu Gen (Rhizoma Phragmitis)

Precautions & Safety

• Dosage: 9–15 g in decoction; whole fruit steeped as prolonged infusion (tea) is the most common preparation; patent extracts and concentrates vary — follow product guidelines
• Contraindicated in Spleen-Stomach deficiency cold presenting with loose stools, abdominal coldness, or cold-damp phlegm; avoid in cases of exterior cold cough without internal heat

Classical TCM Formulas

• Luo Han Guo Cha (罗汉果茶): Luo Han Guo steeped as tea — for dry cough, hoarseness, and thirst.
• Luo Han Guo Gao (罗汉果膏): concentrated Luo Han Guo extract — for chronic dry pharyngitis.
• Modern: mogroside extracts are commercialised worldwide as natural zero-calorie sweeteners (Monk Fruit Sweetener).

Herb Combinations

• Luo Han Guo (罗汉果) + Jie Geng (桔梗) + Gan Cao (甘草): the sweet Lung-soothing trio for dry cough and hoarseness.
• Luo Han Guo (罗汉果) + Pang Da Hai (胖大海) + Mu Hu Die (木蝴蝶): the sweet mucilaginous combination for acute pharyngitis and loss of voice.
• Luo Han Guo (罗汉果) + Sang Ye (桑叶) + Ju Hua (菊花): clears Lung Heat and moistens Dryness for autumn dry cough.

Pharmacology & Research

Antitussive/Expectorant: mogrosides reduce airway inflammation and suppress cough reflex centrally and peripherally.
Antidiabetic: mogrosides (esp. mogroside V) inhibit post-prandial blood glucose elevation without insulinotropic effect; zero glycaemic index.
Antioxidant: mogroside triterpenoids scavenge free radicals and inhibit lipid peroxidation comparably to vitamin C.
Anti-inflammatory: suppresses NF-κB pathway and reduces pro-inflammatory cytokines (IL-6, TNF-α) in vitro.
Antimicrobial: fruit extracts show inhibitory activity against Staphylococcus aureus and common respiratory pathogens in vitro.

Classical Descriptions

• “It treats cough due to Lung heat, assists in clearing and benefiting the throat and voice, and moistens the intestines.” — Lingnan Caiyao Lu (岭南采药录, Xiao Buyao, 1932)