Chelidonium majus, the greater celandine, is a perennial herbaceous flowering plant in the poppy family Papaveraceae.

One of two species in the genus Chelidonium, it is native to Europe and western Asia and introduced widely in North America.

The plant known as lesser celandine (Ficaria verna) is not closely related, as it belongs to the buttercup family Ranunculaceae.

Greater celandine is a perennial herbaceous plant with an erect habit, and reaches 30–120 cm (12–47 in) high.

In Western Asia it is found in the Caucasus, Armenia, Azerbaijan, Georgia, Kazakhstan, Mongolia, Siberia, Iran and Turkey.

Other alkaloids present include methyl 2'-(7,8-dihydrosanguinarine-8-yl)acetate, allocryptopine,[15] stylopine, protopine, cryptopine, hemochelidonine, homochelidonine, norchelidonine, berberine, chelidonine, sanguinarine, chelerythrine,[16] and 8-hydroxydihydrosanguinarine.

[22] Chelidonium is used to make Ukrain, a drug that has been promoted for, but is not known to be effective for, the treatment of cancer and viral infections.

In Germany and Switzerland, extracts of Chelidoni herba are a controversial component of the gastric remedy "Iberogast".

The OTC-preparation is a top-selling product for the company Bayer, which is now under investigation for not warning consumers from possible hepatotoxic side-effects when taking the drug.

As far back as Pliny the Elder and Dioscorides (1st century CE) this herb has been recognized as a useful detoxifying agent.

[31] The modern herbalist Juliette de Baïracli Levy recommended greater celandine diluted with milk for the eyes and the latex for getting rid of warts.