Yan Hu Suo

Corydalis spp.

Chemical Constituents

Alkaloids including cordalines, tetrahydropalmatine (THP) and protapine. [2]


3 to 9 grams of the herb daily as directed. [1]



Traditional Use

Properties of Corydalis spp are found to be bitter acrid and warm. It enters the Heart, Liver and Stomach channels where it acts as an analgesic and strengthens the blood. Yan Hu Suo promotes the movement of Qi and is used for any pain that is associated with trauma or blood stasis. [1] It is also used for pain associated with amenorrhea, dysmenorrhea. [4] 


Analgesic activity: 

Pain relieving effects of corydalis extracts have been reported in laboratory human studies. A small clinical study found that a single oral dose of Corydalis spp decreased pain intensity and pain scores significantly decreased, with dose-related analgesic effects also observed. [5] 

Part of Corydalis spp pain relieving effects may be due to its anti-inflammatory activity, as reported in laboratory animal studies. [6] 

Dopamine agonist activity:

Corydalis spp has been reported in laboratory animal studies to be a dopamine agonist, binding predominantly at the dopamine D(1) receptor. [7] Yan Hu Suo is used in nervousness induced insomnia, agitation and/or anxiety, in part due to isoquinoline alkaloids derived from tyrosine metabolism which influence the neurotransmitter metabolism. [8][9] Extracts from Yan Hu Suo have been reported in a laboratory study to enhance the chemical oxidation of adrenaline and the synthesis of melanine from dihydroxyphenylalanine (DOPA). [10] 

Antitumor activity: 

Corydalis spp has also been reported in laboratory studies to have antitumor activity, nhibiting the metastasis of cancer cells in vitro through the activation of p38 and inhibition of ERK1/2 and SAPK/JNK mitogen-activated protein kinase (MAPK) signaling. [11][12] 

Cardioprotective activity: 

Corydalis spp also has cardioprotective activity as reported in laboratory studies. [13] Laboratory studies have found that corydalis extracts significantly improved heart function and prevented cardiac hypertrophy, with parallel reductions in myocardial fibrosis in rats. [14][15][16] One double-blind, placebo-controlled human study found that tetrahydropalmatine (THP) was superior to conventional drug therapy for treatment of supraventricular arrhythmia. [17] 


No documentation.

Interaction and Depletions

Interaction with other Herbs

No documentation.

Interaction with Drugs

No documentation.

Precautions and Contraindications

Side effects

Evidence suggests hepatotoxicity may occur in some individuals. [3] Use this herb with extreme caution, especially in hepatically compromised individuals. 

Discontinue if allergy occurs. 


Not to be used by pregnant or nursing women.

Age limitation

No documentation.

Adverse reaction

High doses (above 10g) can cause symptoms such as dizziness and abdominal distention. Poisoning is expected at doses above 60grams with onset of symptoms at one to four hours after ingestion. [1]


  1. D. Bensky, S. Clavey, E. Stoger, A. Gamble. Chinese Herbal Medicine Materia Medica, 3rd Edition. , Seattle WA:Eastland Press;2004.607-608.
  2. T. Hu, X. Zhang, S. Ma, Y. Cheng, X. Yao. Chemical constituents from Corydalis yanhusuo. Zhongguo Zhong Yao Za Zhi. Aug2009;34(15):1917-1920.
  3. S. Dharmananda. Jin Bu Huan, corydalis and tetrahydropalmatine: A review prepared for the Rocky Mountain Poison and Drug Center. Institute for Traditional Medicine. 1993; 1-8.
  4. Z. You-Ping. Chinese Matria Medica: Chemistry, Pharmacology and Applications. Florida:CRC Press;.446-449.
  5. C.S. Yuan, S.R. Mehendale, C.Z. Wang. Effects of Corydalis yanhusuo and Angelicae dahuricae on cold pressor-induced pain in humans: a controlled trial. J Clin Pharmacol. Nov2004;44(11):1323-1327.
  6. M. Kubo, H. Matsuda, K. Tokuoka, S. Ma, H. Shiomoto. Anti-inflammatory activities of methanolic extract and alkaloidal components from Corydalis tuber. Biol Pharm Bull. Feb1994;17(2):262-265.
  7. Z.Z. Ma, W. Xu, N.H. Jensen, B.L. Roth, L.Y. Liu-Chen, D.Y. Lee. Isoquinoline alkaloids isolated from Corydalis yanhusuo and their binding affinities at the dopamine D1 receptor. Molecules. 25Sep2008;13(9):2303-2312.
  8. H.L. Schäfer, H. Schäfer, W. Schneider, E.F. Elstner. Sedative action of extract combinations of Eschscholtzia californica and Corydalis cava. Arzneimittelforschung. Feb1995;45(2):124-126.
  9. C. Reimeier, I. Schneider, W. Schneider, H.L. Schäfer, E.F. Elstner. Effects of ethanolic extracts from Eschscholtzia californica and Corydalis cava on dimerization and oxidation of enkephalins. Arzneimittelforschung. Feb1995;45(2):132-136.
  10. E. Kleber, W. Schneider, H.L. Schäfer, E.F. Elstner. Modulation of key reactions of the catecholamine metabolism by extracts from Eschscholtzia californica and Corydalis cava. Arzneimittelforschung. Feb 1995;45(2):127-131.
  11. J.L. Gao, J.M. Shi, K. He, Q.W. Zhang, S.P. Li, S.M. Lee, Y.T. Wang. Yanhusuo extract inhibits metastasis of breast cancer cells by modulating mitogen-activated protein kinase signaling pathways. Oncol Rep. Oct 2008;20(4):819-824.
  12. Y.A. Kim, C.S. Kong, S.S. Yea, Y. Seo. Constituents of Corydalis heterocarpa and their anti-proliferative effects on human cancer cells. Food Chem Toxicol. 21Dec2009.
  13. X.Y. Cheng, Y. Shi, S.L. Zheng, H. Sun, W. Jin. [Studies on chemical constituents in the anti-myocardial ischemia effective fraction of Corydalis yanhusuo]. Zhong Yao Cai. Nov2008;31(11):1656-1658.
  14. C. Wen, L. Wu, H. Ling, L. Li. Salutary effects of Corydalis yanhusuo extract on cardiac hypertrophy due to pressure overload in rats. J Pharm Pharmacol. Aug2007;59(8):1159-1165.
  15. L. Wu, H. Ling, L. Li, L. Jiang, M. He. Beneficial effects of the extract from Corydalis yanhusuo in rats with heart failure following myocardial infarction. J Pharm Pharmacol. May2007;59(5):695-701.
  16. H. Ling, L. Wu, L. Li. Corydalis yanhusuo rhizoma extract reduces infarct size and improves heart function during myocardial ischemia/reperfusion by inhibiting apoptosis in rats. Phytother Res. Jun2006;20(6):448-453.
  17. N. Xiaolin, H. Zhenhua, M. Xin. Clinical and experimental study of dl-tetrahydropalmatine effect in the treatment of supraventricular arrhythmia. J Xi’An Med Univ. 1998;10:150–153.