What is Boldo?
Boldo is an evergreen shrub or small tree native to central Chile, Argentina, Ecuador, Bolivia, and Peru. The plant grows up to 6 m in height. The woody, bitter-smelling leaves are used medicinally. Small, green edible fruits are borne from small, pink-white flowers.
Boldo also is known as boldu, boldus, boldoa, and boldea.
What is it used for?
In Chile, the yellowish-green fruit is eaten, its bark used in tanning, and its wood used for charcoal. Explorers noticed that local South Americans used the leaves medicinally and introduced the herb to North America and Great Britain to prevent or facilitate gas for stomach, bladder, and liver complaints, and as a mild sedative. The plant is used in natural medicine in the treatment of digestive disorders, as a laxative, choleretic (a stimulant of bile secretion), diuretic, and for hepatic diseases. The leaves also have been used for worms, gonorrhea, syphilis, gout, rheumatism, head colds, and earaches. Boldo extract is used as a flavoring for alcoholic beverages.
In vitro and animal studies suggest boldo leaf extract and its part, boldine, possess antioxidant, anti-inflammatory, and antimicrobial effects, as well as potential applications in diabetes, GI disorders, and cancer. However, clinical trials are lacking to support any therapeutic application.
What is the recommended dosage?
No quality clinical trials exist to support therapeutic dosing of boldo leaf extract. Traditional doses include 1 to 2 teaspoons (2 to 3 g) of dry leaf per cup of water; 0.1 to 0.3 mL of liquid extract (1:1 in 45% alcohol) 3 times a day. Commercial preparations may contain ascaridole, which is toxic.
Contraindicated in liver disease and diseases of the bile duct, including gallstones.
Avoid use. Adverse effects have been noted in animal studies.
Boldo ingestion may enhance the anticoagulant effect of warfarin; caution is warranted.
Boldo-related adverse events described in case reports included severe, whole-body allergic reaction, heart rate disorders, and liver toxicity.
High doses are necessary for toxic effects; animal studies documented various toxicities.