Educational information, not medical advice — ask your doctor or midwife.
Mastuerzo is the Latin American name for nasturtium, the garden plant Tropaeolum majus. It has round leaves and bright orange, red or yellow flowers. The leaves, flowers and seed pods are eaten and used as a home remedy.
The plant tastes peppery, like watercress or mustard. In Latin America people have long used the leaf and flower for coughs, colds, wounds and urine complaints. A rinse made from leaves and seeds was also used on the hair and scalp.
Here is the honest verdict: human evidence is thin. Most of what we know comes from lab tests. A few German trials studied a mixed product that pairs nasturtium with horseradish root.
Long use in a tradition is not proof that something works. It is also not proof that it is safe. Both points matter when you read the rest of this page.
Nasturtium is rich in mustard oils. These are the same sharp compounds found in watercress and horseradish.
The plant stores them in a locked form. When you crush or chew the leaf, a plant enzyme unlocks them. The result is benzyl isothiocyanate, the hot-tasting mustard oil.
In test tubes, this mustard oil slows the growth of many bacteria and some fungi. Whether that happens inside a person's body is not settled.
Some of the mustard oil leaves the body in urine. That is the usual reason given for bladder use. It is a proposed route, not a proven one.
In cell and animal studies, the same compounds appear to calm inflammation (swelling and irritation). Those results have not been confirmed in people.
Most people meet mastuerzo as food, in a salad bowl.
Fresh leaves and flowers, eaten raw.
Dried leaf, brewed as a tea.
Fresh juice or crushed leaf, pressed from the plant.
Tincture, which is an alcohol extract sold in dropper bottles.
Tablets or capsules of dried herb. These are often blended with horseradish root.
Pickled seed pods, used like capers.
Hair lotions and scalp rinses, sold in parts of Latin America and Spain.
Creams and washes for minor skin complaints.
The strength of these forms is very different. A salad leaf and a concentrated tablet are not the same thing.
Mastuerzo comes from the Andes. People in Peru and Bolivia grew it for food and medicine long before Europeans arrived.
Spanish traders carried it to Europe in the 1500s. There it became a garden flower and a salad plant, often called Indian cress.
Latin American home healers used the leaf and flower for coughs and chest colds. They also used washes of the leaf on scrapes and sores.
A rinse made from leaves and seeds was popular for thinning hair and dandruff. German herbal practice later turned to urine, sinus and airway complaints, usually with horseradish root added.
Stop the herb and see a doctor if any of these happen.
Fever, chills, or pain in your back or side.
Blood in your urine, or pain passing urine that lasts more than two days.
Bad stomach pain, vomiting, or black stools.
A cough that lasts more than three weeks, or coughing up blood.
Get emergency help for swelling of the face, lips or tongue, a spreading rash, or trouble breathing.
In the United States, Canada and the United Kingdom nasturtium is sold as an ordinary food and as a supplement. In Germany, a fixed blend with horseradish root is licensed as a herbal medicine. In most of Latin America it is simply a garden plant and food.
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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