YARROW - USES, HEALTH BENEFITS & DOSAGE - NEWSHA

Common Name: Yarrow, Common Yarrow, Milfoil

Scientific Name: Achillea millefolium L.

History and Origin

Yarrow is a flowering herbaceous perennial plant that belongs to the family Asteraceae. ⁽¹⁾ Yarrow is one of the oldest known medicinal plants used by humans. The oldest surviving texts to record the use of yarrow in traditional European medicine are by Pliny the Elder and Dioscorides, both during the first century C.E. ⁽²⁾

The word “Achillea” refers to the Greek hero Achilles, who is believed to have carried the plant to treat soldiers' wounds, and the word millefolium, which means “thousand-leaf”, refers to the multipinnate leaves. ⁽³⁾It can be found in northern Asia, North America, Europe and southern Australia. ⁽¹⁾ Full sun is ideal for yarrow growth and blooming.^{(1, 4)} Yarrow is commonly found in meadows, along roadsides, and on dry, sunny slopes. ⁽¹⁾

Yarrow Plant Structure

Yarrow has one or more erect stems (0.2 to 1m tall). Leaves are evenly distributed along the stem. The largest leaves are found near the middle and bottom of the stem. The leaves are bipinnate or tripinnate, almost feathery, 5–20 cm long, and arranged spirally on the stems. They are hairy to varying degrees. ⁽¹⁾

The flowers of millefolium species typically are whitish to yellowish-white, ⁽⁵⁾ but either pink or pale purple flowers are common in mountain areas. ⁽¹⁾ White, five-petaled flowers have yellow stamens and are clustered together in an umbellate-shape on a long straight stalk. ⁽⁶⁾ The volatile oil glands are present on the stem, leaves and petals. ⁽³⁾ The whole plant is aromatic and smells similar to chamomile and pine. ⁽⁶⁾ The yarrow plant is collected during bloom when 80% of the flowers are open. ⁽⁴⁾The flowers, leaves, and stems of the Yarrow plant are used medicinally. ⁽¹⁾

The photo of Achillea millefolium

Yarrow Health Benefits

1. Regulating Blood Pressure

In 2005, the effect of various concentrations of yarrow decoction on the cardiovascular system was studied in rats. The researchers discovered that consuming arrow decoction reduced arterial blood pressure. These findings indicate that yarrow decoction has hypotensive effects in rats. With regard to the non-significant effect of the decoction on heart rate, it is proposed that its hypotensive effect is caused by a decrease in peripheral vascular resistance. ⁽⁷⁾

Also, its hydroalcoholic extract can reduce blood pressure may be due to the presence of phytochemicals such as alkaloids, coumarins, saponins, sterols, tannins and terpenes. ⁽⁸⁾Furthermore, similar to hydrochlorothiazide (a diuretic medication), the hydroalcoholic extract can increase urinary volume and Na⁺ and K⁺excretion. ⁽⁹⁾ Diuretics are used to treat a variety of conditions like hypertension and cardiovascular disorders because they enhance the rate of urine flow and encourage the excretion of urinary sodium from the body. ⁽¹⁰⁾

2. Regulating Blood Glucose Levels

The hypoglycemic properties of yarrow aqueous extract in diabetic mice were investigate in 2018. The findings of this study showed that daily administration of all dosages of the extract (10, 30, 90 and 270 mg/kg), especially 90 and 270 mg/kg, to diabetic mice significantly reduced blood glucose levels. The researchers recommended yarrow aqueous extract as an anti-diabetic supplement. ⁽¹¹⁾

Additionally, a 2020 study on diabetic rats found that yarrow hydroalcoholic extract (25 and 100 mg/kg/day) significantly reduced the fasting blood glucose levels in rats treated with this extract. The effect of yarrow (100 mg/kg) on decreasing blood glucose levels was similar to metformin. (Metformin is an anti-diabetic drug used to treat type 2 diabetes.) Furthermore, the diabetic rats treated with yarrow extract gained weight significantly. ⁽¹²⁾

3. Calming Anxiety and Stress

According to some studies, decreasing estrogen levels in menopausal women increases the risk of stroke. The effect of an aqueous extract of yarrow containing estrogen-like compounds on memory impairment and anxiogenic-like behaviours caused by stroke was investigated in menopausal rats in a 2011 study. According to the results, stroke in menopausal rats caused amnesia and anxiogenic-like behaviors, which were improved by 7 mg/kg of yarrow aqueous extract. It can be concluded that oral administration of yarrow aqueous extract can improve memory impairment and anxiogenic-like behaviors induced by stroke via estrogen receptors in menopausal rats. ⁽¹³⁾

In a 2012 study, the effect of hydroalcoholic extract from its aerial parts on anxiety was evaluated in mice. This study found that the orally administered hydroalcoholic extract of yarrow could calm anxiety. ⁽¹⁴⁾

4. Improving Digestive System Function

Amara are plants that have a high concentration of bitter substances and a stimulating action on gastric secretion and gastrointestinal motility. Bitter substances are a heterogenous group of chemical compounds with the bitter taste as a common feature. Their effect is not only mediated via the mouth by bitter receptors, but they also have a direct effect on the stomach, resulting in hyperemia of the mucosa, increased gastric secretion, and even faster gastric emptying. Amara may also have additional effects, like increasing bile secretion. Aromatica are plants with a high concentration of essential oils that have peristalsis stimulating or spasmolytic (reduction of excessive smooth muscle contractility) properties. Because Achillea millefolium (common yarrow) contains bitter compounds as well as aromatic essential oil, it is classified as “Amara Aromatica”. Due to its anti-inflammatory (antiphlogistic), carminative, and spasmolytic effects, it is used to treat gastric hyposecretion, gastritis, and dyspepsia. ⁽¹⁵⁾

5. Alleviating Peptic Ulcer Disease

According to the findings of a 2006 study, yarrow aqueous extract was effective in protecting the gastric mucosa against acute gastric lesions caused by ethanol and indomethacin, as well as in healing chronic gastric lesions caused by acetic acid. ⁽¹⁶⁾

A 2005 study found that its hydroalcoholic extract was effective in treating gastric ulcers. The study's findings support the use of yarrow in the management of gastric ulcers. ⁽¹⁷⁾

6. Improving Liver Function

In 2012, Iranian researchers discovered that taking aqueous extract of yarrow flower orally after antibiotic administration could protect the liver from antibiotic-induced hepatotoxicity. In this study, researchers evaluate the hepatoprotective properties of the extract by measuring plasma aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities in rats. The results showed that taking the aqueous extract orally (1.2 mg/kg body weight, 4 hours after antibiotic administration) reduced antibiotic-induced elevated serum level of the enzymes and restored the level toward normal levels. The researchers suggested that yarrow aqueous extract could have a hepatoprotective effect due to its significant antioxidant properties and free radical scavenging activity. ⁽¹⁸⁾

Also, according to a 2017 study, alcoholic extract of yarrow can play an important role in the treatment and protection of the liver against various toxic chemicals like carbon tetrachloride (CCL4), which causes hepatotoxicity. The researchers suggested that hepatoprotective activity of the extract might be associated with its high bioactive compounds, including flavonoids. ⁽¹⁹⁾

In addition, in a 2006 study, researchers found that its hydroalcoholic extract exhibited a hepatoprotective effect in mice. The researchers suggested that its hepatoprotective effect might be partly attributed to its observed calcium channel blocking activity. ⁽²⁰⁾

7. Regulating Blood Fat Levels

In a study, the effect of aqueous extract of yarrow aerial parts on blood cholesterol and triglycerides levels was investigated in diabetic rats. The researchers found that consumption of aqueous extract (44.25%) at a dose of 500 mg/kg body weight for 14 days reduced triglycerides, low-density lipoprotein (LDL) and total cholesterol levels. ⁽²¹⁾

According to a 2020 study, its hydroalcoholic extract also significantly reduced triglycerides, total- and LDL-cholesterol levels in yarrow extract-treated rats. In addition, diabetic rats treated with yarrow extract had a considerable increase in HDL-cholesterol serum levels. ⁽¹²⁾

8. Improving Respiratory Tract Function

In a 2009 study, the anti-asthmatic activity of aqueous extract of yarrow flowers (5, 10, 15, 20, 25, 30 mg/ml) was evaluated in animal models. It was found that the yarrow extract had an anti-asthmatic activity by inhibiting airway wall inflammation. The maximum significant anti-asthmatic activity was observed at the doses of 25, 30 mg/ml. ⁽²²⁾

Additionally, a study published in 2020 discovered that yarrow hexanic extract induced a significant relaxant effect on rat tracheal smooth muscle cells by calcium channel blockade and NO release. The researchers suggested that leucodin and achillin are responsible for the observed tracheal relaxant activity of the extract. ⁽²³⁾

9. Anti-Inflammatory

Studies have shown that two classes of secondary metabolites, isoprenoids and phenolics, contribute mainly to the anti-inflammatory properties of yarrow. Also, in a 2009 study, the anti-inflammatory properties of aqueous extract (infusion) of yarrow inflorescences (at a concentration range of 25 - 300 µg/ml) were examined in vitro. The findings confirmed the anti-inflammatory properties of yarrow infusion and its traditional use as an anti-inflammatory drug. ⁽²⁴⁾

What Are Yarrow Side Effects?

1. When taken by mouth: Yarrow is LIKELY SAFE for most people when taken in amounts commonly found in food. Yarrow is POSSIBLY SAFE when taken by mouth in the amounts found in medicine. ⁽²⁵⁾

* However, yarrow products containing a chemical called thujone may be UNSAFE.⁽²⁵⁾ If a thujone content of up to 5% in the volatile oil is taken as a worst-case scenario from the scientific literature data, the amount of thujone in the maximum daily dose of the herbal preparations is theoretically calculated to not exceed 1.5 mg of thujone.” ⁽²⁶⁾

2. Pregnancy and breast-feeding: Yarrow is LIKELY UNSAFE to take orally during pregnancy because it can affect the menstrual cycle and might cause miscarriage. There isn't enough reliable information to know if yarrow is safe to use when breast-feeding. Stay on the safe side and avoid using yarrow. ⁽²⁵⁾

3. Children: Its use in children under 12 years of age is not recommended. ⁽²⁶⁾

4. When applied to the skin: There isn't enough reliable information to know if yarrow is safe or what the side effects might be. When yarrow comes into contact with the skin, it might cause irritation in some people. ⁽²⁵⁾In addition, long-term use of yarrow may make your skin more sensitive to sunlight. ^{(27, 28)}

5. Bleeding disorder: It is observed that hot water infusion of flowering herb has a high haemostyptic activity (an astringent that stops bleeding), whereas pressed juice can prolong blood coagulation. ⁽²⁶⁾In other words, when used in moderation, this herb can stimulate blood clotting, however, in excess, it can act as a blood-thinner in the body. ⁽²⁹⁾Therefore, yarrow might slow blood clotting. In theory, taking yarrow might increase the risk of bleeding in people with bleeding disorders. ⁽²⁵⁾

6. Hormone-sensitive conditions such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: According to one study, a crude extract of yarrow aerial parts has shown estrogenic activity. If you have any condition that might be made worse by exposure to estrogen, avoid using yarrow. ⁽¹⁶⁾

7. Allergy to ragweed and related plants: Yarrow may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many others. If you have allergies, consult with your doctor before taking yarrow. ⁽²⁵⁾The main compound responsible for the sensitization is a sesquiterpene lactone, alpha-peroxyachfolid. ⁽³⁰⁾

8. Surgery: Because yarrow might slow blood clotting, there is a concern that it might increase bleeding during and after surgery. Stop taking yarrow at least 2 weeks before a scheduled surgery. ⁽²⁵⁾

Generally, every person may be allergic to certain herbs and spices. This sensitivity must be first diagnosed by the person and secondarily by the physician. However, these allergic reactions do not cause chronic or acute side effects, and after identifying the allergenic plant and removing it from the diet, allergy-related complications will be eliminated. No company or product can be aware of the allergic reactions of different bodies in advance. The body's incompatibility with one or more specific herbs rarely occurs, but consumers may encounter it anyway.

Nutritional Information

According to a study, dried inflorescences and upper leaves of yarrow, as well as their infusion, contain minerals (Ca, Mg, K, Fe, Cu, Mn, Zn) and Vitamin B9 (folic acid/folates). ⁽³¹⁾

Yarrow Daily Dosage

To make a herbal tea, use 2 gm of finely cut herb. A cup of this herbal tea is drunk 3 to 4 times daily. It is best to make fresh tea for each use. ⁽³⁰⁾

* High doses of yarrow may turn urine dark brown. ⁽²⁸⁾

Bioactive Compounds

According to the literature, the pharmacological effects are attributed primarily to the volatile oil, proazulenes and other sesquiterpene lactones, and phenolic compounds such as dicaffeoylquinic acids and flavonoids. However, these components can be found in very different quantities in various plant materials.

The main active compounds of yarrow include Flavonoids (apigenin, luteolin, isorhamnetin, rutin); phenolic acids (caffeic, salicylic acids); tannins; amino acids (alanine, histidine, leucine, lysine); fatty acids (linoleic, palmitic, oleic acids); vitamins (ascorbic acid, folic acid); alkaloids and bases (achiceine, achilleine, betaine, choline); alkanes (tricosane); polyacetylenes; saponins; phytosterols (β-sitosterol); sugars (dextrose, glucose, mannitol, sucrose); and coumarins.

The herb also contain volatile oils (essential oil), mostly β-caryophyllene, linalool, camphor, borneol, 1,8-cineole, and sesquiterpene lactones composed of guaianolides, mainly achillicin (a proazulene), achillin, leucodin, and germacranolides (achillifolin, dihydroparthenolide, millefin). The volatile oil content and its chemical composition may vary depending on the source of the plant material and the number of chromosomes present in the plant.⁽²⁶⁾ According to the European Pharmacopoeia, dried flowering tops of Achillea millefolium L. should contain “not less than 2 ml/kg of volatile oil (essential oil) and not less than 0.02% chamazulene (proazulenes). ⁽³²⁾

According to a 2006 study, the volatile oil of A. millefolium may contain α-thujone and β-thujone, with mean values of 2.26% and 1.61%, respectively. Nevertheless, the published evidence confirms that thujone is a minor component of the volatile oil of A. millefolium; its concentration is considered too low to present a risk to human health. ⁽²⁶⁾

Best Time to Consume

Between meals.

Possible Drug Interactions

Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs): Yarrow might slow blood clotting. Taking yarrow along with medications that also slow clotting might increase the chances of bruising and bleeding. Some medications that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen (Anaprox, Naprosyn, others), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, warfarin (Coumadin), and others.

Lithium: Yarrow might have an effect like a water pill or "diuretic." Taking yarrow might decrease how well the body gets rid of lithium. This could increase how much lithium is in the body and result in serious side effects. Talk with your healthcare provider before using this product if you are taking lithium. Your lithium dose might need to be changed. ⁽²⁵⁾

Medications for high blood pressure (Antihypertensive drugs): Yarrow may lower blood pressure and could strengthen the effects of prescription drugs taken to lower blood pressure. Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDIURIL), furosemide (Lasix), and many others. ⁽²⁷⁾

Medications that decrease stomach acid: Yarrow might increase stomach acid. By increasing stomach acid, yarrow might decrease the effectiveness of some medications that decrease stomach acid. Some medications that decrease stomach acid include:

1. (H2-Blockers): such as cimetidine (Tagamet), ranitidine (Zantac), nizatidine (Axid), and famotidine (Pepcid).

2. Antacids: such as calcium carbonate (Tums, others), dihydroxyaluminum sodium carbonate (Rolaids, others), magaldrate (Riopan), magnesium sulfate (Bilagog), aluminum hydroxide (Amphojel), and others.

3. Proton pump inhibitors: such as omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), and esomeprazole (Nexium). ⁽²⁵⁾

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

1. Anticonvulsants: Some medications used to prevent seizures include phenobarbital, primidone (Mysoline), valproic acid (Depakene), gabapentin (Neurontin), carbamazepine (Tegretol), phenytoin (Dilantin), and others.

2. Barbiturates: Some sedative medications (barbiturates) include amobarbital (Amytal), butabarbital (Butisol), mephobarbital (Mebaral), pentobarbital (Nembutal), phenobarbital (Luminal), secobarbital (Seconal), and others.

3. Benzodiazepines: Some benzodiazepines include alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium), lorazepam (Ativan), midazolam (Versed), temazepam (Restoril), triazolam (Halcion), and others.

4. Drugs for insomnia, such as zolpidem (Ambien), zaleplon (Sonata), eszopiclone (Lunesta), ramelteon (Rozerem). ⁽²⁷⁾

Traditional Use

Yarrow infusion is widely used in Europe as a remedy to treat digestive problems, diabetes, hepato-biliary diseases and amenorrhea. It is also used for its antitumor, antimicrobial, anti-inflammatory and antioxidant properties, among others. The decoction is used to treat digestive and intestinal disorders, as well as skin and mucosa inflammations. ⁽³³⁾ Yarrow also is listed in the Indian Ayurvedic Pharmacopoeia for fevers and wound healing. ⁽²⁶⁾

The European Union Herbal Monograph on Millefolii herba accepted the following traditional uses:

- For the treatment of temporary loss of appetite and mild, spasmodic gastrointestinal complaints, including bloating, and flatulence. For this purpose, 1.5-4 g of the comminuted herbal substance in 150-250 ml boiling water is used orally as a herbal infusion 3 or 4 times a day between meals. The duration of use is 2 weeks. If the symptoms persist for more than 2 weeks during the use of the herbal infusion, a doctor should be consulted.

- For the treatment of minor spasms associated with menstrual periods. For this purpose, 1-2 g of the comminuted herbal substance in 250 ml boiling water is used orally as a herbal infusion 2-3 times daily. The duration of use is 1 week. If the symptoms persist for more than 1 week during the use of the herbal infusion, a doctor should be consulted.

- For the treatment of small superficial wounds. For this purpose, 3-4 g of the comminuted herbal substance in 250 ml water is applied to the affected area in a form of impregnated dressing 2-3 times daily. The duration of cutaneous use is 1 week. If the symptoms persist for more than 1 week during the use of the herbal infusion, a doctor should be consulted. ⁽²⁶⁾

Some Questions about Yarrow

Is yarrow good for eczema?

An infusion of yarrow flowers may help heal eczema when applied externally as a wash. ⁽¹⁾

Is yarrow good for the lungs?

According to one study, aqueous extract of yarrow flowers has an anti-asthmatic activity due to the inhibition of airway wall inflammation. ⁽²²⁾

How often should you drink yarrow tea?

A cup of freshly made tea to be drunk 3 to 4 times daily between meals. ⁽³⁰⁾

Is yarrow a blood thinner? / Does yarrow help stop bleeding?

It is observed that hot water infusion of the flowering herb has high haemostyptic activity (an astringent that stops bleeding), whereas pressed juice can prolong blood coagulation. ⁽²⁶⁾In other words, this herb can stimulate blood clotting when used in moderation, but when used excessively, it can thin blood. ⁽²⁹⁾

Does yarrow make you sleepy?

Yarrow is a mild sedative; it can increase the effects of other drugs you take for anxiety or insomnia. ⁽²⁷⁾

Who should not take yarrow?

Pregnancy and breast-feeding: Yarrow is LIKELY UNSAFE to take orally during pregnancy because it can affect the menstrual cycle and might cause miscarriage. There isn't enough reliable information to know if yarrow is safe to use when breast-feeding. Stay on the safe side and avoid using yarrow. ⁽²⁵⁾