Yarrow

Achillea millefolium

Common & Folk Names

• Milfoil
• Soldier’s Woundwort
• Nosebleed
• Bloodwort
• Carpenter’s Weed
• Knight’s Milfoil
• Herbe Militaris
• Staunchweed
• Thousand Leaf

Plant Family

Asteraceae (Formerly Compositae) – The Daisy Family

Geographic Location

Yarrow is native to temperate regions of Europe and Asia. It has been naturalised throughout North America and is now found across most of the world in temperate and subtropical zones.

Habitat

Yarrow is extremely adaptable and grows in a wide range of environments. It is commonly found in meadows, pastures, lawns, roadsides, fields, and disturbed habitats from sea level to mountainous regions. It thrives in both cultivated and wild settings.

Growing Conditions

Sun: Yarrow needs full sun for optimal growth, though it can tolerate partial shade.

Soil: Yarrow thrives in well-drained, poor to average soil. It is remarkably drought-tolerant and can handle poor, compacted ground. It prefers neutral to slightly alkaline pH.

Propagation: Yarrow is easily grown from seed, division, or cuttings. Seeds can be sown directly after the last frost. It can become invasive due to its spreading rhizomes.

Care: Yarrow requires minimal care once established. Deadheading spent flowers encourages continued blooming. It is hardy in USDA Zones 3-9.

Harvesting Guidelines

Yarrow should be harvested when the plant is in full bloom, typically from early to mid-summer. It is recommended to harvest on a sunny, dry day after the morning dew has dried, as this gives the best concentration of volatile oils. The flowers should be bright white or pink. Harvest the aerial parts (leaves, stems, and flowers) and dry in a warm, shaded, well-ventilated area to preserve the volatile oils.
The leaves can also be collected at any time during their growth cycle, but it is best to harvest them just before flowering for maximum potency.

Parts Used

• Aerial parts (leaves, stems, and flowers)
• Roots (occasionally)

Constituents & their Actions

Volatile Oils:

These compounds are responsible for yarrow’s aroma and many of its therapeutic properties. The volatile oils provide anti-inflammatory, antimicrobial, and antispasmodic actions. Some of the main volatile oils in yarrow are:

• Azulenes (chamazulene, formed during distillation)
• Sabinene
• 1,8-Cineole
• Camphor
• α-Pinene
• β-Pinene

The main actions of these volatile oils are:

• Anti-inflammatory
• Antimicrobial
• Antispasmodic
• Expectorant

Sesquiterpene Lactones:

These bitter compounds are potent anti-inflammatory agents that work by inhibiting pro-inflammatory pathways in the body. They also contribute to yarrow’s antimicrobial and digestive stimulant properties. Some of the main sesquiterpene lactones in yarrow are:

• Achillicin
• Achillin
• Leucodin

The main actions of these sesquiterpene lactones are:

• Anti-inflammatory
• Antimicrobial
• Digestive bitter

Flavonoids:

These polyphenolic compounds are antioxidants that protect cells from oxidative damage whilst also contributing to anti-inflammatory and vascular tonic effects. Some of the main flavonoids in yarrow are:

• Apigenin
• Luteolin
• Quercetin
• Kaempferol
• Rutin
• Casticin

The main actions of these flavonoids are:

• Antioxidant
• Anti-inflammatory
• Antispasmodic
• Vascular tonic

Alkaloids:

These nitrogen-containing compounds provide specific hemostatic (blood-staunching) and astringent actions. The primary alkaloid, achilleine, is particularly well-documented for its ability to stop bleeding. Some of the main alkaloids in yarrow are:

• Achilleine
• Betonicine
• Stachydrine

The main actions of these alkaloids are:

• Hemostatic (stops bleeding)
• Astringent

Tannins:

These compounds provide a powerful astringent action, precipitating proteins to tighten tissues and reduce secretions. Yarrow contains condensed tannins that contribute to its wound-healing and tissue-toning properties.
The main action of tannins is:

• Astringent (toning effect)

Salicylic Acid:

This compound is a precursor to aspirin and provides analgesic and anti-inflammatory effects similar to those of aspirin, though milder.
The main actions of salicylic acid are:

• Analgesic (pain relief)
• Anti-inflammatory

Actions with Mechanisms

Hemostatic (Stops Bleeding): The alkaloid achilleine directly contracts the smooth muscle of peripheral blood vessels and capillaries, which in turn reduces blood flow to the affected area. Additionally, the high tannin content precipitates proteins in the wound, forming a physical seal over the damaged tissue. This dual action makes yarrow effective for both internal and external bleeding, including nosebleeds, cuts, wounds, and excessive menstrual flow.

Vulnerary (Wound Healing): The azulenes and sesquiterpene lactones inhibit inflammatory mediators such as leukotrienes and TNF-α, which in turn reduces swelling and promotes tissue repair. The antimicrobial volatile oils prevent infection in wounds, whilst the astringent tannins help to close and protect the wound site. Together, these actions accelerate the healing process.

Diaphoretic (Promotes Sweating): Yarrow stimulates blood flow to the surface of the skin and opens the pores, which in turn promotes sweating and helps to break fevers. This action is particularly indicated at the onset of acute infections such as colds and flu, especially when the fever is accompanied by a closed, dry skin. By driving heat and pathogens out through the skin, yarrow supports the body’s natural fever response.

Anti-inflammatory: The azulenes, sesquiterpene lactones, flavonoids, and salicylic acid in yarrow work through multiple pathways to reduce inflammation. The azulenes inhibit the enzyme cyclooxygenase (COX), whilst the sesquiterpene lactones inhibit the NF-κB inflammatory pathway. The flavonoids stabilise cell membranes and reduce the production of pro-inflammatory prostaglandins. This multi-targeted approach makes yarrow useful for both acute and chronic inflammatory conditions affecting the digestive tract, urinary system, skin, and musculoskeletal system.

Antispasmodic: The flavonoids (particularly casticin) and volatile oils in yarrow relax smooth muscle throughout the body, which in turn relieves cramping and spasms. This makes yarrow useful for menstrual cramps, intestinal colic, tension headaches, and spasmodic conditions of the urinary and respiratory systems.

Astringent: The tannins in yarrow precipitate proteins on the surface of tissues, which in turn tightens and tones them. This action reduces excessive secretions and bleeding, making yarrow useful for conditions such as diarrhoea, haemorrhoids, excessive menstrual flow (menorrhagia), and weeping skin conditions.

Antimicrobial: The volatile oils and sesquiterpene lactones in yarrow disrupt the cell membranes of bacteria and fungi, which in turn leads to the leakage of cellular contents and microbial death. This action has been demonstrated against a range of bacteria, fungi, and protozoa, supporting yarrow’s traditional use for treating infections.

Hypotensive (Lowers Blood Pressure): Yarrow promotes peripheral vasodilation, which in turn reduces resistance in the circulatory system and lowers blood pressure. Additionally, its mild diuretic action helps to reduce blood volume. This makes yarrow useful as a gentle cardiovascular tonic for those with hypertension.

Digestive Bitter: The sesquiterpene lactones in yarrow stimulate the bitter taste receptors on the tongue, which in turn promotes the production of digestive enzymes, bile, and gastric juices. This enhances overall digestive function and makes yarrow useful for poor appetite, sluggish digestion, and digestive complaints related to insufficient secretions.

Main Use

Yarrow’s primary use is as a hemostatic and vulnerary for wounds, cuts, bruises, and bleeding. It is nearly unmatched as a first-aid herb for traumatic injuries, combining the ability to stop bleeding, prevent infection, reduce inflammation, and accelerate healing.
Internally, yarrow’s main use is as a diaphoretic for the initial, feverish stage of acute infections such as colds and flu. It is particularly indicated when the fever is accompanied by a closed, dry skin and the body needs support in “opening up” and driving the pathogen out through sweating.
Yarrow is also used internally as an astringent and anti-inflammatory for excessive menstrual bleeding, hemorrhoids, diarrhea, and inflammatory conditions of the digestive and urinary tracts.

Preparations

Fresh Poultice: The most effective first-aid application for wounds. Crush fresh leaves and flowers and apply directly to cuts, scrapes, bruises, and nosebleeds to stop bleeding and prevent infection. Replace as needed.

Tea/Infusion (Hot): 1–2 teaspoons of dried herb per cup of boiling water. Steep covered for 10–15 minutes to preserve volatile oils. Drink hot to induce sweating for fevers. Can also be used as a wash for wounds or a gargle for sore throats.

Tea/Infusion (Cold): 1–2 teaspoons of dried herb per cup of cold water. Steep for 4–8 hours for a more bitter, astringent tonic for digestive or urinary issues.

Tincture: (1:5 in 40–50% alcohol). 2–4 mL, 3 times daily. For acute fevers, internal bleeding, or menstrual irregularities.

Sitz Bath: A strong infusion (4–6 tablespoons of dried herb per litre of water) added to a bath to soothe haemorrhoids, pelvic congestion, and menstrual cramps.

Infused Oil/Salve: Infuse dried aerial parts in oil for 4–6 weeks. Strain and combine with beeswax to create a salve for topical application to wounds, bruises, and inflamed skin.

Vinegar: An excellent preparation for preserving the mineral content and for use as a long-term circulatory and digestive tonic.

Dosage

Dried Herb (Tea): 2–4 grams (approx. 1–2 tsp), 3 times daily.

Tincture (1:5, 40–50%): 2–4 mL (approx. 40–80 drops), 3 times daily.

Topical Use: Apply fresh poultice, infused oil, salve, or wash as needed, 2–4 times daily.

Safety & Drug Interactions

Scientific Evidence

Wound Healing & Anti-inflammatory: In vivo studies in animal models have confirmed that yarrow extracts accelerate wound healing, reduce inflammation, and decrease wound surface area more effectively than standard controls. The azulenes and sesquiterpene lactones are primarily responsible for these effects.

Antimicrobial: Multiple in vitro studies demonstrate the antibacterial and antifungal activity of yarrow essential oil and extracts against a range of bacteria (including Gram-positive and Gram-negative species) and fungi (including Candida species). This supports its traditional use for preventing wound infections.

Antispasmodic: Studies on isolated smooth muscle (ileum, uterus, trachea) confirm the spasmolytic effect of yarrow extracts, particularly the flavonoid casticin. This supports its traditional use for menstrual cramps, colic, and cramping.

Hemostatic: The hemostatic activity of the alkaloid achilleine is well-documented in pharmacological litreature. Clinical observations support its use for nosebleeds, cuts, and excessive menstrual bleeding.

Traditional Use: Yarrow’s use is recorded in ancient texts from multiple cultures, including Greek (Dioscorides), Chinese, Native American, and European traditions, for wound healing, fever management, and bleeding disorders.

Western Energetics

Temperature: Warming in its diaphoretic action (opens pores and moves circulation to the surface); Cooling in its anti-inflammatory and bitter actions. This dual nature makes yarrow particularly useful for fevers where heat needs to be driven out through the skin.

Moisture: Drying. Its astringent and diaphoretic actions are strongly drying, making it useful for damp conditions such as weeping wounds, excessive secretions, diarrhea, and congestive states.

Tissue State: Primarily for Tension/Constriction (fever with closed pores, cramping, spasms) and Damp/Stagnation (congestion, infection, excessive secretions). Also for Heat/Excitation with bleeding.

Taste

Bitter: The dominant taste, signaling yarrow’s digestive stimulant, anti-inflammatory, and cooling properties. The bitter quality also indicates its action on the liver and its ability to move stagnation.

Astringent: A pronounced drying, puckering sensation that reflects yarrow’s ability to tighten tissues, reduce secretions, and stop bleeding.

Pungent: A slightly spicy, aromatic quality from the volatile oils, indicating yarrow’s warming, stimulating, and antimicrobial properties.

Plant Lore

The genus name Achillea honors the Greek hero Achilles, who, according to Homer’s Iliad, used yarrow to staunch the bleeding wounds of his soldiers during the Trojan War. This ancient association with battlefield medicine has given yarrow many of its folk names, including Soldier’s Woundwort and Herbe Militaris.
In European folklore, yarrow was believed to have protective and divinatory powers. It was used in love charms, hung over doorways to ward off evil spirits, and placed under pillows to bring prophetic dreams. Young women would place yarrow under their pillows while reciting a rhyme to dream of their future husbands.
In China, the dried stalks of yarrow’s relative (Achillea sibirica) have been used for centuries in I Ching divination, where they are cast to determine hexagrams.
Yarrow was also called “Nosebleed” because inserting a fresh leaf into the nostril was a traditional folk remedy to stop nosebleeds–though paradoxically, it was also used to induce nosebleeds as a form of bloodletting for headaches and high blood pressure.
The name “Milfoil” comes from the Latin mille (thousand) and folium (leaf), referring to the finely divided, feather-like leaves that make yarrow easily recognizable.

Additional Information

Yarrow is a “directional” herb in fever management; it opens the pores and moves circulation to the surface, guiding the body’s response to infection outward. This makes it particularly useful at the very onset of acute infections.

It is a quintessential “battlefield herb,” embodying the principle of healing under pressure and stopping acute loss. The combination of hemostatic, vulnerary, and antimicrobial actions makes it nearly perfect for traumatic injuries.

The vibrant green, feathery leaves and white or pink flower clusters make yarrow easy to identify in the wild, making it an accessible first-aid remedy for hikers and foragers.

As a companion plant in the garden, yarrow is believed to enhance the health and vigor of neighboring plants and attract beneficial insects.

Yarrow can accumulate minerals from the soil, making it a valuable addition to compost or as a nutrient-rich mulch.

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