About This Herb*
Traditional Chinese Medicine background and properties
Herb Description*
Pei Lan is a fragrant herb that specialises in resolving digestive problems caused by excess moisture and humidity in the body. It is best known for treating bloating, nausea, loss of appetite, bad breath, and a sweet sticky taste in the mouth. It is also a go-to herb for summer ailments caused by heat and humidity, such as feeling heavy-headed, feverish, and sluggish.
Herb Category*
Main Actions*
- Aromatically Transforms Dampness
- Awakens the Spleen and Opens the Appetite
- Releases the Exterior and Resolves Summerheat
How These Actions Work*
'Transforms dampness aromatically' means Pèi Lán uses its fragrant nature to cut through Dampness that has accumulated in the middle burner (the digestive system). When Dampness clogs the Spleen and Stomach, digestion stalls and the person feels bloated, nauseous, and heavy. Pèi Lán's aromatic quality penetrates and disperses this Dampness, restoring normal digestive movement. It is especially valued for treating a condition called pí dàn (脾瘅, 'Spleen Dampness-Heat'), where Dampness and Heat accumulate in the Spleen channel and produce a characteristic sweet, greasy taste in the mouth, excessive saliva, and bad breath.
'Awakens the Spleen and opens the appetite' describes how the herb revives sluggish digestive function. When Dampness weighs down the Spleen, appetite disappears and food feels unappetising. Pèi Lán's fragrant, pungent quality 'wakes up' the Spleen, helping it resume its job of transforming food and fluids. This is why it is commonly used for people who feel full and bloated with no desire to eat, or who have a thick, greasy tongue coating.
'Releases the exterior and resolves summerheat' means Pèi Lán can address the early stages of illness caused by summerheat and Dampness, such as feeling feverish, heavy-headed, and chest-congested during hot, humid weather. Its neutral temperature (unlike Huò Xiāng, which is slightly warm) makes it particularly suitable when there is a Damp-Heat component, as it resolves Dampness without adding extra warmth.
Patterns Addressed*
In TCM, symptoms cluster into recognizable patterns of disharmony that reveal what's out of balance in the body. Pei Lan is traditionally associated with these specific patterns.
The following describes this herb's classification within Traditional Chinese Medicine theory and is provided for educational purposes only.
Why Pei Lan addresses this pattern
Pèi Lán directly targets the pathomechanism of this pattern: Dampness congesting the Spleen and Stomach, impairing their transport and transformation functions. Its acrid taste disperses and moves stagnation, while its aromatic nature penetrates turbid Dampness that ordinary drying herbs cannot reach. Because it enters both the Spleen and Stomach channels and has a neutral temperature, it resolves Dampness without generating unwanted Heat or further injuring fluids. It is the classical herb of choice for pí dàn (Spleen Dampness), as referenced in the Sù Wèn's discussion of treating a sweet taste in the mouth with 'lán' (orchid/eupatorium) to 'remove stale Qi.'
A practitioner would look for one or more of these signs
Epigastric and abdominal distension and fullness
Nausea and vomiting
Poor appetite, no desire to eat
Sweet, greasy taste in the mouth with bad breath
Excessive sticky saliva
Why Pei Lan addresses this pattern
When Dampness in the middle burner persists and generates Heat, it produces the Damp-Heat pattern characterised by a foul, sweet, greasy taste, thick yellow tongue coating, and turbid secretions. Pèi Lán's neutral temperature is a key advantage here: unlike warmer aromatic herbs such as Huò Xiāng, Pèi Lán resolves Dampness without adding Heat to an already warm situation. Its pungent quality disperses the sticky, turbid Dampness while its aromatic nature cuts through the foul, stale quality that Damp-Heat produces. Classical texts specifically identify Pèi Lán as the principal herb for this 'Spleen Dampness-Heat' presentation.
A practitioner would look for one or more of these signs
Foul breath with sweet greasy mouth taste
Copious sticky saliva
Epigastric fullness and distension
Thick, greasy, yellow tongue coating
Why Pei Lan addresses this pattern
During hot, humid seasons, the body can be invaded by Summerheat combined with Dampness. This produces a distinctive illness with fever, heaviness, chest congestion, and digestive disruption. Pèi Lán's dual ability to release the exterior and resolve internal Dampness makes it well suited to this pattern. It enters the Lung channel (which governs the body's surface) to help vent Summerheat outward, while simultaneously entering the Spleen and Stomach to resolve the Dampness component internally. Its neutral temperature prevents it from aggravating the Heat aspect of the pattern.
A practitioner would look for one or more of these signs
Low-grade fever with fatigue in hot weather
Feeling of heaviness in the head and body
Chest stuffiness and oppression
Nausea with no appetite
TCM Properties*
Neutral
Acrid / Pungent (辛 xīn), Aromatic (芳香 fāng xiāng)
Whole plant / Aerial parts (全草 quán cǎo)
This is partial information on the herb's TCM properties. More detailed information is available on the herb's dedicated page
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.