Official name: Cinnamomi Ramulus
English name: Cassia Twig
Scientific name: Cinnamomum cassia Presl
Chinese name: 桂枝
Chinese phonetic name: guì zhī
The dried young branch of Cinnamomum cassia Presl (Fam. Lauranceae). 
Place of origin
Cassia Twig is mainly produced in Guangdong, Guangxi, Hainan and Yunnan provinces in China. 
Cassia Twig is pungent and sweet in flavor, warm in nature, and mainly manifests its therapeutic actions in the heart, spleen and lung meridians. 
Major Chemical Constituents
Major active components in Cassia Twig capsule include cinnamylaldehyde, cannamic acid, 2-methoxy cinnamic acid, 1-4-diphenyl-butane-dione, coumarin, β-sitosterol, diterpenoids and polymer-glycoside etc. 
Drug actions in TCM
Cassia Twig can induce perspiration by releasing the exterior, release muscles, warm and smooth meridian, promote menstruation, reinforce yang, relieve palpitation, and send down adverse rising qi.
Traditional Uses in TCM
Traditionally, cassia twig is often used to treat common cold, cold pain in stomach and abdominal regions, missed periods, joint pain, fluid retention, palpitations, respiratory problems, gastro-intestinal neurosis (ben tun qi) with a feeling of gas rushing up through the chest to the throat from the lower abdomen. 
- Cassia twig is suitable for upper respiratory conditions.
Cassia twig specializes in disseminating yang qi towards external body and promote blood flowing in body surface, which enhance the body’s resistance against external pathogens, release muscle for perspiration, and thus expel wind and coldness in the external body. For example, in cold and flu individuals who present chills, runny nose and no sweating, cassia twig can work with ephedra to activate lung qi and expel the wind and coldness through perspiration, a sample formula is the Ephedra Decoction (Ma Huang Tang); for those with sweating, cassia twig can work with white peony root to harmony the internal and external body, release muscle for effective perspiration to relieve the cold and flu, a classic formula is the Cinnamon Twig Decoction (Gui Zhi Tang).
- Cassia twig is suitable for painful conditions due to blood coldness
Cassia twig can warm and smooth meridian, expel coldness to help relieve pain. Chest pain or angina, palpitation that due yang insufficient in the chest, cassia twig is often combined with immature bitter orange and longstamen onion bulb for relief. For cold pain in the stomach and abdomen that due to deficiency and excessive cold, cassia twig is often combined with white peony root and maltose for relief. Excessive cold is also associated with irregular periods, missed periods, menstrual pain and abdominal pain after delivery, cassia twig can work with angelica root and medicinal evodia fruits for relief. Some joint and muscle pain cases that due to wind, cold and dampness accumulation, cassia twig often combined with aconite root to expel the pathogens and arrest the pain.
- Cassia twig aids spleen’s transportation of body fluids
Cassia twig regulates fluid metabolism and expel phlegm and static fluid by invigorating spleen and kidney and bladder functioning. Cassia twig is often combined with poria, largehead atractylodes rhizome, polyporus and oriental water-plantain rhizome to treat conditions like body fluid retentions, chronic bronchitis, asthma, rheumatic arthritis and dizziness. A sample formula is the Five Ingredients Powder with Poria (wu ling san).
- Cassia twig aids heart yang, smooths blood vessels and arrests palpitations
For individuals with palpations or abnormal heart beats, cassia twig can work with liquorice root, ginseng and dwarf lily-turf tuber for relief, a sample formula is the Honey Processed Liquorice Root Decoction (zhi gan cao tang). Ben tun qi refers to a sudden colic that starts in lower abdomen, rushes straight upward and stops in the chest or throat, palpitations and restless is the usual accompanied symptoms. Cassis twig might be largely used in the remedy.
Studies showed that cassia twig has antimicrobial activity, antipyretic analgesic effect, sedative anticonvulsant effect, anti-inflammatory effect, effect on immune system, diuretic effect, increase coronary blood flow, anti-oxidation and hypolipidemic effect. 
Administration and dosage
For decoction, using 3〜10g.
Adverse effect and cautions
The pungent flavor and warm nature of Cassia Twig can harm yin and activate blood. It is not indicated for those with feverish or bleeding conditions. Women in pregnancy or excessive menstruation should also use with caution. 
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