The leaves from the Horopito tree were traditionally used by the Maori to treat stomach pain and diarrhoea, probably due to its astringent (tissue tightening) and antiseptic properties.  Skin conditions were treated with bruised leaves that had been steeped in warm water or chewed before application. The peppery constituents (polygodial) of Horopito stimulate the circulation when it is applied topically, and taken internally.

Topical uses: fungal infections such as Candida albicans and ringworm, wounds, cuts, burns and painful bruises. Leaves were chewed for toothache.   Internally, Horopito was used for treating diarrhoea, stomach ache and poor circulation.

The main active constituent of Horopito is known as polygodial. Polygodial is a component of the “hot taste” common in traditional Japanese cuisine, and it has been shown to exhibit significant antifungal and antibacterial properties. Researchers from Kolorex in New Zealand demonstrated the ability of polygodial, isolated from Horopito, to inhibit the growth of Candida albicans (the yeast that causes thrush), and other researchers have shown it to be effective against a variety of yeast-like fungi.