Traditional herbs often have a colorful history of medicinal use. Yarrow, legend has it, was named after the Greek hero Achilles (the name of the genus is Achillea). Some sources claim Achilles used yarrow to heal his warriors on the battlefield, as it’s a great styptic and wound healer.
Yarrow leaves were also used in traditional cooking, though the flavor is quite strong, similar to tarragon.
The medicinal properties of yarrow primarily belong to the flowers, though.
Yarrow the Wound-Healer
Given the legend of Achilles, it’s no wonder that yarrow is a star of wound healing—internally and externally.
In the Stomach Mucosa
This study shows that Achillea millefolium in a water extract can help to heal stomach ulcers, both acute and chronic, with no signs of toxicity even with long-term consumption.
In the Vaginal Mucosa
This study demonstrates that an ointment made from yarrow and St. John’s Wort (excellent for nerve pain) encourages healing of episiotomy incisions (of the vaginal wall during childbirth).
In the Skin
In this animal study, even a water extract significantly improved superficial wound healing. (One would think an ointment would perform better, though, as it would be more likely to absorb.)
This test tube study also showed that yarrow’s skin healing properties might involve decreased inflammation, and increased moisture retention.
Yarrow for Relaxing Smooth Muscle
Several of yarrow’s medicinal properties depend upon its ability to relax smooth muscle, the involuntary muscles of the organs. The mechanisms here seem to be natural calcium channel blocking effects, as well as stimulating cholinergic (acetylcholine) receptors, and release of the vasodilating nitric oxide.
Because yarrow is anti-spasmodic, it’s useful for spasms of various different types of involuntary muscle.
In the uterus
Yarrow acts as a tonic to the uterus, helping it to relax. It’s been used traditionally for amenorrhea (lack of menses), but it’s also used for menorrhagia (excessively heavy bleeding) as well. This is because it has astringent properties (it stops bleeding), yet it simultaneously can slow blood clotting.
In other words, yarrow brings balance.
In the intestines
Cramping intestinal pain such as IBS might therefore experience symptomatic relief from yarrow. (As with all of these symptoms, it’s always important to also find and treat the root cause, though.)
In the blood vessels
The blood vessels, too, are comprised of smooth muscle. Both the release of nitric oxide and the calcium channel blocking activities of yarrow should help to relax blood vessels and thus, lower blood pressure. This animal study shows that, in fact, they do.
In the lungs
What dilates the blood vessels can also help to relax and dilate bronchioles in the lungs too. This same study shows that yarrow can be helpful for asthma.
Yarrow for Liver Support and Protection
Yarrow is another option for liver support, helping to protect the liver from toxic insults and decreasing inflammation.
Yarrow for Anxiety
This animal study shows that the essential oils of yarrow species demonstrate significant anti-anxiety effects.
They were shown to do so via a different mechanism of action as compared to the common family of anxiety medications, benzodiazepines.
Yarrow for Neurological Disease
Various alkaloid constituents in yarrow have been studied for a wide variety of chronic neurological illnesses. This may be in part because the constituent luteolin appears to cross the blood-brain barrier well.
This study specifically shows that yarrow’s antioxidant and anti-inflammatory properties may be of benefit for epilepsy, multiple sclerosis, Parkinson’s, Alzheimer’s, and stroke victims. This animal study also showed that yarrow decreased the damage from encephalomyelitis.
Yarrow’s antioxidants demonstrated anti-seizure effects in this animal study.
Luteolin was shown in this animal study to protect against cognitive decline.
Cautions with Yarrow
For all its benefits, yarrow also does carry some potential risks.
While yarrow is wound healing and antispasmodic, due to its potential to slow blood clotting, it’s a good idea to stop taking it before surgery.
Also, since its uterine properties can play both sides of the fence, there’s a concern that it could lead to miscarriage. It’s therefore contraindicated in pregnancy.
This animal study suggests that it may decrease sperm production. If male fertility is a concern, best to avoid it until there is more data.
Yarrow also belongs to the asteraceae family, so if you’re allergic to ragweed, you might also be sensitive to yarrow.
The Upshot: How to Use Yarrow Medicinally
As you probably noticed, the studies mentioned above used yarrow in a variety of forms.
For mental/emotional benefits, the essential oil was studied. This can be diffused.
For wounds, a salve or an ointment preparation would be best.
For internal ulcers, tea would work well. Tea, tinctures, or powdered capsules would also work well for most other indications mentioned.