Educational information, not medical advice — ask your doctor or midwife.
What is Good King Henry?
Good King Henry is a leafy green plant, eaten much like spinach. Its botanical name is Blitum bonus-henricus. It was once a common sight in European kitchen gardens.
The young leaves were boiled as a green. The young shoots were cooked like asparagus. In Germany it is called Guter Heinrich.
Today it is mainly a garden vegetable and an old folk remedy. There are almost no human studies on it as a medicine. Long traditional use is not proof that it works, and not proof that it is safe.
How is it supposed to work?
There is no proven medical mechanism for Good King Henry in people. Most of what is said about it comes from its food value and from folk ideas.
The leaves carry fibre, iron, vitamin C and plant pigments. A serving of cooked greens adds those to a meal. That is nutrition, not treatment.
The plant also holds saponins, soap-like plant compounds. In laboratory work, saponins from related plants can irritate the gut lining and may loosen stools. Whether the amounts in a normal serving do anything in a person has not been shown.
Folk use put crushed leaves on boils and sores. No trial has tested that on human skin.
How is it sold or used?
Most people meet it as a plant, not a product.
- Fresh young leaves, cooked as a green. - Young shoots, cooked and served like asparagus. - Seeds and plants for the garden, sold by seed firms.
- Dried leaf, used as a folk tea. - Crushed fresh leaf, used in old poultices for the skin.
It is rare as a capsule or tincture. Where such products exist, they are not standardised and their content is not checked the way a medicine is.
What did tradition claim?
Good King Henry was a poor household's spring green across much of Europe. It was grown near cottages and farm walls for hundreds of years.
In England it was called Lincolnshire spinach and poor man's asparagus. The first spring shoots were valued after a winter of stored food. German folk named it Guter Heinrich, said by some to set it apart from Bad Henry, the poisonous dog's mercury.
Folk healers used the leaves on boils, sores and chapped skin. The seeds and leaves had a name as a gentle laxative. It was also fed to hens and geese to improve their condition.
These are records of custom. They were not tests, and they do not tell you whether the plant helps or harms you.
When to see a doctor
Stop eating it and get medical advice if you notice any of these:
- Pain in your side or lower back, or pain when you pass urine. - Blood in your urine. - Stomach pain or diarrhoea that does not settle in a day or two. - A skin sore that gets hotter, redder, more painful or starts to spread.
Get urgent help if your lips, tongue or throat swell, or if you struggle to breathe. That can be a severe allergic reaction.
If you think you have eaten a wild plant you could not name, call your local poisons line or emergency number straight away.
In the UK, the EU and the US, Good King Henry is treated as an ordinary food plant and garden vegetable. It is not approved as a medicine anywhere. Any capsule or tincture sold from it is a supplement, and its contents are not checked the way a drug is.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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