Corydalis yanhusuo is a species of genus Corydalis. Research has indicated that the alkaloid dehydrocorybulbine (DHCB), extracted from the roots of the plant, can be helpful in reducing neuropathic pain. Tetrahydropalmatine is a major constituent alkaloid which also has analgesic activity. Corydalis yanhusuo also contains the alkaloids glaucine and palmatine. It also contains the acetylcholinesterase inhibitor corydaline. N-methyltetrahydroprotoberberines with κ-opioid receptor agonist activity have been isolated from C. yanhusuo.