# Plant Monograph: Bugleweed
**Name of plant:**
Bugleweed
**Catch phrase (Carmina Gadelica or traditional invocation if available):**
No specific Carmina Gadelica invocation is recorded for bugleweed. Traditional European herbal practice associated the plant with cooling, drying, and soothing qualities.
**Family:**
Lamiaceae — Mint family
**Genus and species:**
*Lycopus europaeus* L.
**Other names:**
European bugleweed, gypsywort, water horehound, wolf's foot, European water horehound, *Lycopus europaeus*, German bugleweed
**Brief introduction:**
Bugleweed is a perennial herb of wet ground belonging to the mint family. It is native to much of Europe and parts of western Asia and is commonly found beside streams, ponds, ditches, marshes, and other damp habitats. The plant has square stems and small white flowers marked with reddish or purple spots. Several species of *Lycopus* have been used medicinally, particularly in European herbal traditions. Bugleweed is especially notable for traditional applications involving the thyroid, respiratory system, and minor bleeding.
**Traditional uses:**
* Used traditionally for symptoms associated with an overactive thyroid.
* Used as an astringent for minor bleeding and wounds.
* Used traditionally for coughs and respiratory irritation.
* Used as a cooling herb for fevers and excessive perspiration.
* Used traditionally for nervousness, palpitations, and related symptoms.
**Historical use:**
* European herbalists employed *Lycopus* species for conditions characterized by excessive heat or perspiration.
* Bugleweed was traditionally used for wounds and minor bleeding because of its astringent qualities.
* Preparations were used historically for cough and respiratory complaints.
* European herbal medicine associated the herb with disorders involving an overactive heart or circulation.
* By the nineteenth and twentieth centuries, *Lycopus* species had become particularly associated with traditional treatment of hyperthyroid symptoms.
**Parts used and method of use:**
* Above-ground flowering herb
* Fresh or dried leaves and stems
Used as:
* Infusion or tea
* Liquid extract or tincture
* Fresh-plant preparations
* Dried herb in traditional medicinal formulations
**Use in healing (modern herbal practice):**
* Traditionally used to reduce symptoms associated with mild hyperthyroidism, particularly palpitations and excessive sweating.
* Used traditionally for nervousness and restlessness associated with thyroid overactivity.
* Used as an astringent for minor bleeding.
* Used traditionally for cough and respiratory irritation.
* Occasionally employed by herbal practitioners as a cardiovascular-supportive herb when palpitations are associated with thyroid overactivity.
**Pharmacology and biochemistry:**
* **Rosmarinic acid** — a phenolic compound with antioxidant and anti-inflammatory activity.
* **Labiatic acid and related phenolic compounds** — characteristic constituents of *Lycopus* species that have been investigated for effects on thyroid hormone metabolism.
* **Hydroxycinnamic acids and flavonoids** — contribute to the plant's antioxidant and potentially anti-inflammatory activity.
Mechanisms:
* Extracts of *Lycopus* species have demonstrated inhibition of aspects of thyroid hormone synthesis and peripheral thyroid hormone activity in experimental studies.
* Phenolic constituents contribute antioxidant and anti-inflammatory effects.
* Traditional astringent effects are associated with the plant's tannin and polyphenol content.
Overall profile: Bugleweed is one of the more specifically thyroid-oriented European medicinal herbs. Experimental and historical evidence suggests that *Lycopus* preparations can reduce thyroid activity, although modern clinical evidence is limited and inconsistent. It should therefore not be treated as a substitute for diagnosis or medically supervised treatment of hyperthyroidism.
**Common dosage:**
* Dried herb infusion: approximately 2–4 g dried herb per cup of water, traditionally taken up to 3 times daily
* Liquid extract: approximately 2–4 mL of a 1:5 extract, up to 3 times daily
* Tincture: approximately 2–4 mL of a 1:5 tincture, up to 3 times daily
* Standardized preparations: follow the manufacturer's dosage because concentrations vary considerably
**Safety factors (including side effects):**
* Bugleweed may lower thyroid activity and should be used cautiously in anyone with hypothyroidism.
* It may cause gastrointestinal upset, particularly at higher doses.
* People taking thyroid replacement medication should not use medicinal doses without professional supervision.
* Pregnancy and breastfeeding are situations in which medicinal use should generally be avoided because adequate safety data are lacking.
* Long-term unsupervised use is inappropriate because suppression of thyroid function may develop or existing thyroid disease may be masked.
**First aid / adverse reaction response:**
* Excessive thyroid suppression symptoms: discontinue use and seek medical assessment, particularly if severe fatigue, cold intolerance, or marked slowing of the heart develops.
* Palpitations, dizziness, or fainting: stop use and seek medical evaluation; urgent care is appropriate for severe or persistent symptoms.
* Gastrointestinal upset: discontinue or reduce exposure and seek advice if symptoms are severe or persistent.
* Allergic reaction: discontinue use; seek emergency medical attention for difficulty breathing, facial swelling, or widespread rapid-onset hives.
**Drug interactions:**
* **Thyroid hormones, including levothyroxine:** bugleweed may theoretically oppose thyroid replacement therapy.
* **Antithyroid medicines:** additive thyroid-suppressing effects are possible.
* **Cardiovascular medicines:** theoretical additive effects may occur because thyroid function and cardiac rate are closely connected.
* Because clinical interaction data are limited, medicinal use should be discussed with a healthcare professional when prescription medicines are being taken.
**Horticultural requirements:**
* USDA / Canadian zone: approximately USDA 4–9
* Soil pH: 5.5–7.5
* Light requirements: Full sun / partial shade
* Moisture: Moist to wet; tolerates waterlogged soils better than most garden herbs
* Other notes (growth habit, harvest timing, etc.):
* Perennial herb spreading by underground rhizomes; typically about 30–100 cm tall.
* Small white flowers with reddish or purple markings appear in summer.
* Harvest the aerial portions during flowering.
* Naturally occurs beside streams, ponds, ditches, marshes, wet meadows, and other damp soils.
* Propagated by seed, division, or rhizome sections; provide consistently moist soil.
**Sampling of clinical reports / studies:**
* Small clinical studies and older pharmacological investigations of *Lycopus europaeus* and related *Lycopus* species have investigated their effects on symptoms of hyperthyroidism.
* Experimental research has demonstrated effects of *Lycopus* extracts on thyroid hormone metabolism and thyroid-stimulating pathways.
* Phytochemical studies have identified rosmarinic acid, lithospermic-acid-related compounds, flavonoids, and other phenolic constituents.
* European ethnomedical literature documents the use of *Lycopus* species for thyroid-related symptoms, excessive sweating, palpitations, respiratory complaints, and minor bleeding.
* **Overall assessment of evidence:** Traditional use and experimental evidence provide a plausible basis for thyroid-related activity, but high-quality modern clinical evidence is insufficient to establish an effective standardized dose or confirm efficacy for hyperthyroidism.
Educational Use Only: The information presented on this page is provided for educational, historical, and informational purposes only. ArdNemeton na Tuatha and Bhùth Draoi do not provide medical advice. Always consult your physician and pharmacist before using any herb, mushroom, supplement, or botanical product for medicinal purposes. Traditional uses described herein do not constitute medical claims.