Purple Loosestrife plant - Lythrum Salicaria (Lythraceae)

Medicinal Use of Purple Loosestrife – Lythrum Salicaria (Lythraceae)


Attractive perennial growing to about 5 ft (1.5 m). Has straight red stems, pointed lance-shaped leaves, and spikes of brilliant purple flowers.

Habitat & Cultivation

Purple loosestrife is native to Europe but well-established in the wild in North America. It thrives in marshes and along rivers and streams, to altitudes of 3,300 ft (1,000 m). It is gathered when in flower in summer.

Parts Used

Aerial parts.


Purple loosestrife contains salicarin, a glycoside (vitexin), tannins, a volatile oil, mucilage, and plant sterols.

History & Folklore

In 1654, the herbalist Nicholas Culpeper praised this herb, writing that “the distilled water is a present remedy for hurts and blows on the eyes, and for blindness … it also cleareth the eyes of dust or any other thing gotten into them, and preserveth the sight.” A common plant in Ireland, purple loosestrife was much used there against diarrhea.

Medicinal Actions & Uses

The astringent purple loosestrife is mainly employed as a treatment for diarrhea and dysentery. It can be safely taken by people of all ages; some herbalists recommend it to help arrest diarrhea in breastfeeding babies. The herb may also be used to treat heavy periods and for inter-menstrual bleeding.

Externally, it is applied as a poultice or lotion to wounds, leg ulcers, and eczema, and used to treat excess vaginal discharge and vaginal itching. Purple loosestrife is now little used to treat eye problems, but, as Culpeper’s experience suggests, the herb could be worth further investigation as a remedy for disorders of the eyes and vision.


In animal experiments, extracts of the flowers and leaves have been shown to be hypoglycemic—lowering blood-sugar levels. The plant is also thought to have antibiotic activity.