Yarrow is a hardy perennial wildflower (Achillea millefolium) native to temperate regions of Europe and Asia, now naturalized worldwide. Its name traces back to the Greek myth that Achilles used it to staunch soldiers' wounds — a story that reflects its centuries-long reputation as a first-aid herb. Every part of the plant above ground has been used medicinally, from its feathery leaves to its small white-to-pink flower clusters.

Yarrow works through several overlapping pathways. Its tannins and the alkaloid achilleine help tighten blood vessels and promote clotting at wound sites, which explains its traditional styptic (bleeding-stopping) use. Its flavonoids — particularly apigenin — relax smooth muscle, which is why it eases menstrual cramps and digestive spasms. The herb also has a mild bitter quality that stimulates bile flow and digestive juices, supporting healthy gut function. Anti-inflammatory compounds including chamazulene (produced when the plant is steam-distilled) and caffeic acid derivatives help calm swelling and irritation both internally and on the skin.

Tea made from dried aerial parts is the most traditional and widely researched form for internal use. Tinctures (1:5, 25–45% alcohol) offer a more concentrated and shelf-stable option. Capsules standardized to flavonoid content are available for those who dislike the bitter taste. Topically, yarrow creams and salves are used for minor wounds and skin inflammation. The essential oil should always be diluted before skin contact.

• Menstrual cramps and heavy periods
• Wounds and minor bleeding (topical)
• Fever and common cold
• Digestive upset and bloating
• Irritable bowel and gut spasms
• Skin inflammation and eczema (topical)
• Urinary tract discomfort
• High blood pressure (mild support)
• Anxiety and nervous tension

• Excessive wound-site bleeding (topical styptic use)
• Recurrent digestive discomfort when used as a daily bitter tonic

• Yarrow tea (dried aerial parts) — The most direct and traditional way to consume yarrow — a standard infusion of dried leaves and flowers delivers the full spectrum of its active flavonoids, bitter compounds, and volatile oils.
• Chamomile tea — Contains the same key flavonoid apigenin as yarrow and provides overlapping antispasmodic and anti-inflammatory support for the gut and menstrual system — a natural companion herb.
• Ginger — Shares yarrow's anti-nausea, anti-inflammatory, and gut-soothing properties, making it a useful dietary complement especially for digestive and menstrual complaints.
• Parsley — Rich in apigenin and luteolin — the same flavonoids that give yarrow its antispasmodic and anti-inflammatory effects — and easy to add to everyday meals.
• Celery — Another apigenin-rich plant that supports the same smooth-muscle relaxation pathway, useful for people looking to reinforce yarrow's benefits through diet.

• Allergic skin rash or contact dermatitis (especially topical use)
• Increased sun sensitivity of the skin (phototoxicity) with topical use
• Mild nausea or stomach upset if taken on an empty stomach
• Headache (rare, usually with high doses of the essential oil)
• Drowsiness at high doses
• Not safe during pregnancy (may stimulate uterine contractions)

• Recommended daily: Tea: 2–4 g of dried aerial parts steeped in 150–250 ml hot water, 2–3 times daily. Tincture (1:5, 25% alcohol): 3–5 ml up to 3 times daily. Capsules: 300–500 mg standardized extract, 2–3 times daily. Topical: apply cream or salve 2–3 times daily to affected area.
• Best time of day: For digestive support, take 15–30 minutes before meals. For menstrual or nervous system support, evening use (including as a bedtime tea) is traditional and practical. For fever, take as a warm tea at symptom onset.
• With or without food: Can be taken with or without food; taking with a small amount of food reduces the chance of nausea in sensitive individuals. For digestive bitter effects, take before meals on a relatively empty stomach.
• Time to effect: Acute effects (fever, digestion, bleeding) within hours to 2 days; menstrual and chronic benefits within 2–4 weeks of consistent use.
• How long to take it: Safe for short-term use (up to 4–6 weeks) without concern. For ongoing support (e.g., menstrual cycle use), cycling — using it in the 1–2 weeks before your period and stopping afterward — is a practical and traditional approach. Avoid continuous daily use beyond 3 months without a practitioner's guidance.