Herb library · Herb · Rumex acetosella
Sheep sorrel
A small, sour-leaved weed of pastures and worn fields. It is best known today as one of the four herbs in the Essiac tea mixture; it has not been studied on its own in people.
Traditional use
Found throughout North America and Europe. The sour leaves have been eaten as a wild green. King's American Dispensatory (1905) records that the Eclectic physician John Scudder suggested a tincture of the fresh plant for what he called a tendency to degeneration of tissue. In the 20th century it became one of the four herbs in Essiac, a tea mixture promoted in Canada as a cancer remedy.
What studies show
No studies in people of this herb on its own yet. What is known of it comes from the traditions that use it.
- Insufficient
Cancer and general health: no study of sheep sorrel on its own in people was found. The National Cancer Institute reports that no clinical trials of Essiac, the mixture that contains it, have been published in peer-reviewed journals. In lab tests a sheep sorrel extract slowed blood platelets from clumping; this has not been checked in people.
Be careful of
Cautions
- ConditionKing's American Dispensatory says the leaves of both garden and sheep sorrel contain an oxalate salt, and records poisoning from eating garden sorrel leaves freely. People with kidney stones or kidney disease should avoid it.
- ConditionDo not use Essiac or sheep sorrel in place of cancer care.
- InteractionBecause a lab study found it slows platelet clumping, take care if you use blood thinners or antiplatelet medicines; this effect has not been tested in people.
- PregnancyNo safety information for pregnancy or breastfeeding was found; avoid it then.
- Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.
From the old books
What herbals and dispensaries of the past printed. History, in their words.
“This weed is found in abundance throughout the United States, growing in pastures, waste grounds, and worn fields, flowering all summer (G.—W.). A strong tincture of the fresh plant (℥viii to alcohol, 76 per cent, Oj), in doses ranging from 1 to 30 drops, has been suggested by Dr. Scudder (Spec. Med.) as a remedy where there is a “tendency to degeneration of tissue,””
Sources
- Essiac/Flor Essence (PDQ®) — Patient Version (National Cancer Institute) (opens in a new tab) · NIH · read September 25, 2026
- Rumex acetosella Inhibits Platelet Function via Impaired MAPK and Phosphoinositide 3-Kinase Signaling (Chin J Integr Med, 2022) — PubMed record (opens in a new tab) · NIH · read September 25, 2026
Reviewed September 25, 2026.