Pang Da Hai 胖大海 — Chinese Herbal Medicine

Pang Da Hai (胖大海) At a Glance

• Herb: Pang Da Hai
• Chinese name: 胖大海 (Pang Da Hai)
• Latin name: Semen Sterculiae Lychnophorae
• Nature: Cold
• Taste: Sweet
• Meridian: Lung
• Category: Resolve Phlegm Heat

Pang Da Hai, the seed of Sterculia lychnophora, is one of Chinese medicine’s most recognisable throat herbs — commonly steeped as a tea for hoarse or lost voice caused by Lung heat. Its sweet, cold nature allows it to simultaneously moisten the Lung, clear fire, and descend accumulated heat through the Large Intestine. Lightweight yet effective, it is often used as a single-herb remedy for acute vocal strain and throat inflammation.

Actions & Therapeutic Effects

• Clears Lung heat and opens the voice
• Moistens the Lung and stops dry cough
• Resolves phlegm and soothes the throat
• Clears heat and unblocks the bowels

Clinical Applications in TCM

• Hoarseness or sudden loss of voice from Lung heat — steep 2–4 seeds alone in boiling water, or combine with She Gan (射干) and Mu Hu Die (木蝴蝶)
• Dry, irritating cough with scanty phlegm due to Lung dryness-heat — pair with Sang Ye (桑叶) and Pi Pa Ye (枇杷叶)
• Sore, swollen throat from wind-heat invasion — combine with Jie Geng (桔梗) and Gan Cao (甘草)
• Vocal strain from overuse with underlying heat — use alone as a daily infusion alongside voice rest
• Heat accumulation in the Large Intestine with dry constipation — steep in warm water and drink on an empty stomach
• Mouth sores and throat inflammation with constipation — combine with Jue Ming Zi (决明子) and Lü Cha (绿茶)

Precautions & Safety

• Dosage: 2–4 whole seeds steeped in boiling water as an infusion; decoction equivalent 3–9 g
• Contraindicated in cold-type cough, wind-cold patterns, and spleen-stomach deficiency cold
• Avoid in patients with chronic loose stools or diarrhoea — mild laxative action may aggravate
• Use with caution during pregnancy; not recommended for long-term daily use
• Quality note: seeds must fully expand in hot water; seeds that fail to swell may be adulterated or aged

Classical TCM Formulas

• Pang Da Hai Cha (胖大海茶): Pang Da Hai 1-2 seeds steeped in hot water — the standard treatment for acute pharyngitis and hoarseness.
• Li Yan Cha (利咽茶): Pang Da Hai + Mu Hu Die + Jie Geng — acute pharyngitis.
• Pang Da Hai is most effective when the seed is allowed to fully swell in hot water for 5-10 minutes.

Herb Combinations

• Pang Da Hai (胖大海) + Jie Geng (桔梗) + Gan Cao (甘草): the sore-throat trio — Pang Da Hai coats and soothes, Jie Geng opens and directs, Gan Cao harmonises.
• Pang Da Hai (胖大海) + Mu Hu Die (木蝴蝶): the two mucilaginous seeds — powerful soothing for acute pharyngitis and loss of voice.
• Pang Da Hai (胖大海) + Bo He (薄荷) + Chan Tui (蝉蜕): clears Wind-Heat and benefits the throat.

Pharmacology & Research

Demulcent: seeds swell up to 40–60× their volume in water, coating and soothing inflamed mucous membranes of the throat and bronchi.
Anti-inflammatory: sterculia polysaccharides inhibit pro-inflammatory cytokines, reducing mucosal oedema in the upper respiratory tract.
Laxative: sterculia acid and swelling mucilage exert a mild osmotic and bulk effect, softening stool and easing Large Intestine heat accumulation.
Antibacterial: aqueous extracts demonstrate in vitro inhibitory activity against Streptococcus pyogenes and other common pharyngeal pathogens.
Antioxidant: flavonoid constituents scavenge free radicals, supporting tissue repair in heat-damaged mucosal surfaces.

Classical Descriptions

• “治火閉音啞，開音止嗽，清熱解毒，並治一切熱症勞傷吐衄下血，消毒去暑。” — 本草綱目拾遺 (Ben Cao Gang Mu Shi Yi), Zhao Xuemin (趙學敏), Qing Dynasty, c. 1765