Yarrow (Achillea millefolium) is a perennial herb with a long history of use in traditional medicine. It is recognized by its distinctive, finely divided, feather-like leaves, which earned it the common name “milfoil” (meaning “thousand-leaf”). The plant produces small, densely clustered flowers, typically white, that bloom throughout the Northern Hemisphere. Historically, yarrow was known as “soldier’s woundwort,” and its genus name, Achillea, is derived from the Greek hero Achilles, who was said to have used it to treat injuries.
Topical Applications for Skin and Bleeding
One of the most recognized traditional uses of yarrow is its ability to staunch the flow of blood from minor wounds, a property known as hemostasis. When crushed, the leaves and flowers can be applied directly to cuts and abrasions to accelerate the clotting process. This effect is primarily attributed to tannins, which are astringent compounds that contract and tighten blood vessels and tissues.
The alkaloid achilletin also contributes to this blood-staunching effect. Beyond controlling bleeding, yarrow provides a mild anti-inflammatory effect when applied topically, helping to soothe irritated skin and reduce swelling.
The plant also possesses antimicrobial properties that help cleanse the wound site and may prevent localized infection. Applying a poultice or infused oil can support the natural healing process for bruises and insect bites.
Internal Use for Digestive and Systemic Relief
When consumed as a tea or tincture, yarrow functions as a mild bitter tonic, stimulating digestive processes. Its bitter compounds, including the glycoside achillein, encourage the production of saliva and stomach acids, aiding in the efficient breakdown of food. This is helpful for traditional uses involving appetite loss and mild dyspeptic ailments.
Yarrow is also valued for its diaphoretic action—the ability to safely induce sweating—which is beneficial for reducing fevers associated with colds and influenza. By promoting peripheral blood circulation and encouraging perspiration, the body can more effectively cool itself and manage febrile conditions.
The volatile oil contains compounds like chamazulene, known for their anti-inflammatory effects. This systemic activity, combined with flavonoids, helps relieve generalized discomfort and mild spastic conditions in the gastrointestinal tract, soothing intestinal cramping.
Preparation Methods and Culinary Uses
The most common method for preparing yarrow for internal use is as an infusion, or tea, which extracts the water-soluble compounds. To prepare a simple infusion, steep approximately one to two teaspoons of dried yarrow herb in a cup of boiling water for about 10 to 15 minutes before straining. For a more concentrated preparation, a tincture is made by macerating the fresh or dried aerial parts of the plant in a solvent like alcohol over a period of four to six weeks.
For topical applications, a poultice is easily made by crushing fresh yarrow leaves to release the medicinal oils and applying the resulting mass directly to the skin. An infused oil or salve can also be created for soothing skin irritations or chronic inflammation.
Beyond medicine, yarrow has minor culinary applications, offering a mild, bitter flavor that can be used as a seasoning in savory dishes. Historically, the flowers were used to flavor beer and alcoholic ferments. Yarrow also serves a non-medicinal purpose as a natural insect repellent, utilizing its strong aromatic volatile oils in tinctures or sprays to deter pests like mosquitoes and ticks.
Safety Profile and Contraindications
While yarrow is generally considered safe when used appropriately, potential sensitivities and contraindications exist. Individuals with known allergies to plants in the Asteraceae family (such as ragweed, daisies, or chrysanthemums) should avoid yarrow due to cross-reactivity. Contact dermatitis is the most commonly reported adverse reaction to topical application of the fresh plant.
Yarrow is considered likely unsafe during pregnancy because its traditional emmenagogue properties can stimulate menstrual flow and potentially relax uterine smooth muscle. Women who are breastfeeding are also advised to avoid its use due to insufficient reliable safety data. Furthermore, yarrow should not be taken internally by individuals on blood-thinning medications, such as warfarin, as its hemostatic properties may interfere with their intended effect and alter clotting time.