Bugleweed

The leaves and flowers of this plant from the mint family are used medicinally. Both bugleweed and its European cousin, gypsywort (Lycopus europaeus), grow in very wet areas.

The modern applications of bugleweed, unlike many medicinal plants, do not match its traditional use. Historically, bugleweed and related species were used to treat coughs and as a sedative.¹ Today, the main use of this herb is for treating mild hyperthyroidism.

Lithospermic acid and other organic acids are believed to be responsible for bugleweed’s activity. These acids decrease levels of several hormones in the body, particularly thyroid-stimulating hormones² and the thyroid hormone thyroxine (T4).³ Bugleweed inhibits the binding of antibodies to the thyroid gland.⁴ These antibodies can cause the most common form of hyperthyroidism, Graves’ disease. All these actions may help explain bugleweed’s benefit in people with mildly overactive thyroids.

The German Commission E monograph recommends 1–2 grams of the whole herb per day.⁵ Intake of tincture should be limited to 1–2 ml three times a day. Bugleweed is often combined with other herbs used to treat mildly overactive thyroid function, including lemon balm (Melissa officinalis) and gromwell (Lithospermum ruderale).

Excessive intake of bugleweed by people with thyroid disease or use by healthy people may cause a potentially harmful decrease in thyroid function. Thyroid disease is dangerous and should only be treated under the supervision of a healthcare professional. However, long-term use of bugleweed is considered safe for people with hyperthyroidism.⁶ Bugleweed should not be taken by people with hypothyroidism. Bugleweed should also not be used during pregnancy and breast-feeding.⁷