Legend has it that yarrow (Achillea millefolium) was named after Achilles, the Greek mythical figure who used it to stop the bleeding wounds of his soldiers. Popular in European folk medicine, yarrow contains flavonoids (plant-based chemicals) that increase saliva and stomach acid, helping to improve digestion. Yarrow may also relax smooth muscle in the intestine and uterus, which can relieve stomach and menstrual cramps.

Few scientific studies have investigated yarrow's use as an herbal medicine. Traditionally, it was used for three types of ailments: applied topically, for wounds and minor bleeding; to reduce inflammation, especially in the digestive tract; and to alleviate anxiety or insomnia (as a sedative). Today, yarrow may be considered for the following uses:

• Loss of appetite
• Indigestion or heartburn
• To increase urine flow
• Amenorrhea (irregular menstrual cycle)
• Menstrual cramps and pain
• Muscle spasms
• Inflammation
• To fight infection
• Fever (brings temperature down through sweating)
• To reduce bleeding
• Wound healing

Yarrow, a member of the aster family, is closely related to chrysanthemums and chamomile. It flourishes in a sunny and warm habitat, and is frequently found in meadows and along roadsides, as well as on dry, sunny slopes. It grows as a simple, upright, and hairy stem, usually under 3 feet. Yarrow blooms between June and September. The flowers are typically white, but either pink or pale purple flowers are common in mountain areas. The petals are densely arranged in flattened clusters, and the leaves look like feathers. The plant spreads rapidly.

The flowers, leaves, and stems of the yarrow plant are used for medicinal purposes. It is collected while in bloom.

Yarrow is available in the following forms:

• Dried or fresh herb
• Capsules or tablets
• Tinctures
• Liquid extracts

Pediatric

There have been no studies evaluating the use of yarrow in children. Talk to your doctor before giving yarrow to a child.

Adult

The following are recommended adult doses for yarrow:

• Tea: Steep 1 - 2 tsp. dried herb in 1 cup boiling water, strain and cool. Drink 3 times per day.
• Capsules: 2 - 4 g, 3 times per day
• Extract (1:1, 25% ethanol): 1 - 4 mL (20 - 120 drops) 3 times per day
• Tincture (1:5; 40% ethanol): 2 - 4 mL (40 -120 drops) 3 times per day

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.

If you are sensitive to plants in the aster family (chrysanthemums, daisies, ragweed), you may be sensitive to yarrow, either taken orally or applied topically.

Yarrow may make your skin more sensitive to sunlight.

Pregnant women should not take yarrow, because its ability to relax the smooth muscle of the uterus could cause miscarriage. At least one study found that yarrow was associated with reduced fetal weight in rats. Other studies have shown an increase in the percentage of abnormal sperm among male rats treated with yarrow extract. No studies have evaluated yarrow's use in breastfeeding women. If you are nursing, talk to your doctor before taking yarrow.

Yarrow may interact with the following medications:

Medications to reduce stomach acid -- Because yarrow may increase the production of stomach acid, it can interfere with both over-the-counter and prescription drugs including:

• Cimetidine (Tagamet)
• Famotidine (Pepcid)
• Ranitidine (Zantac)
• Esomeprazole (Nexium)
• Omeprazole (Prilosec)
• Lansoprazole (Prevacid)

Medications for high blood pressure -- Yarrow may lower blood pressure slightly, and could make the effects of prescription drugs taken to lower blood pressure stronger.

Drugs that cause sleepiness -- Because yarrow is a mild sedative, it can increase the effects of other drugs you take for anxiety or sleepiness. These include:

• Anticonvulsants, such as phenytoin (Dilantin)
• Barbiturates
• Benzodiazepines, such as alprazolam (Xanax) and diazepam (Valium)
• Drugs for insomnia, such as zolpidem (Ambien), zaleplon (Sonata), eszopiclone (Lunesta), ramelteon (Rozerem)

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