Nasturtium (Tropaeolum majus)
What Is Nasturtium?
Nasturtium is the common name for Tropaeolum majus, a plant of the Tropaeolaceae family, native to the Andes of South America. The material in circulation is leaf, flower, seed — leafy growth taken above ground. Most people search for it simply as Nasturtium; suppliers, pharmacopoeias and interaction databases list it as Tropaeolum majus, and matching the two is the first step in identifying what is actually in a product. Its character is described as peppery, green, mustard-sharp, which is often how the raw material is checked for quality.
Nasturtium entered the reference literature through use rather than through chemistry. Older sources are concerned with where it grows, when it is gathered and how it is prepared, questions that still shape the material on sale today. Beyond its practical use it carries cultural associations — shield-shaped leaves — protection and victory in flower lore.
Today most searches for Nasturtium come from people reading about congestion, lung support, antibacterial and infection, or checking how it sits alongside a medication they already take. The use most often documented in the literature is benzyl isothiocyanate has broad antibacterial activity, followed by german cohort data support use in recurrent UTI and bronchitis with horseradish.
How Does Nasturtium Work?
Nasturtium works as a mixture rather than a single isolated compound, and its profile is usually described by the class of constituents present in leaf, flower, seed rather than by one marker molecule.
Before its chemistry was known, Nasturtium was judged by what it did in the cup: how strongly it brewed, how it tasted, and how little or much was needed. Those notes are why particular preparations survived and others did not.
The research base is developing: there are human trials, though sample sizes and designs vary, and this profile cites 1 source. Reported findings centre on a prospective cohort of over 2,000 patients found nasturtium + horseradish comparable to standard antibiotics for uncomplicated UTI and sinusitis, with fewer adverse events. Where research exists, it examines benzyl isothiocyanate has broad antibacterial activity, german cohort data support use in recurrent UTI and bronchitis with horseradish and Vitamin C rich leaf and flower. These are areas of study, not established outcomes, and results differ by preparation and dose.
How the plant is prepared changes what you actually get. Its constituents move readily into glycerin — so a preparation made in another medium will not carry the same fraction of the plant, which is why traditional recipes specify one over another.
Nasturtium is studied as a whole preparation because isolating one fraction tends to behave differently from the material it was taken out of — a recurring finding across the plant-chemistry literature.
Because these constituents are processed by the same pathways that handle many medicines, Nasturtium is documented as interacting with antibiotics and anticoagulants. That is a question of shared metabolism rather than of potency, and it is the main reason the plant is listed in interaction references at all.
Dose, plant part and growing conditions all shift the constituent profile, so two products carrying the name Nasturtium can differ substantially; this is why reference entries specify leaf, flower, seed and, where they exist, standardisation markers.