Clinical trials have considered yarrow as a potential therapy (used both topically and systemically, as well as alone or in combination with other treatments) for chronic kidney disease,[1] cirrhosis,[2] chemotherapy-related fatigue,[3][4] and multiple sclerosis.[5]
When used alone, those with chronic kidney disease taking 1.5 g of powdered yarrow flower (3 days a week over 2 months) saw a marginal reduction in plasma nitrite and nitrates, while those taking a placebo saw increases in the same biomarkers.[1] Liver compresses containing yarrow are sometimes used in integrative medicine; however, metastatic cancer patients undergoing chemotherapy saw no substantive reductions of self-reported fatigue and psychological distress when liver compresses containing yarrow were applied externally over the liver,[4] and heart rate variability analysis in a subset of participants were not conclusive.[3].
As a combination therapy, yarrow seems to be somewhat more successful. A six-month study of people with cirrhosis found that those taking a multi-ingredient (Tamarix gallica 16 mg, iron-based ayurvedic preparation Mandur Bhasma 33 mg, and extracts of Capparis spinosa 65 mg, Cichorium intybus 65 mg, Solanum nigrum 32 mg, Cassia occidentalis 16 mg, Terminalia arjuna 32 mg, and Achillea millefolium 16 mg) tablet three times daily saw reductions in serum ALT and AST (biomarkers of liver damage), and abdominal swelling, compared to placebo.[2] Similarly, when a yarrow extract containing 0.28 mg/g of luteolin and 1.58 mg/g of apigenin was studied as an add-on therapy for multiple sclerosis, the groups taking 250 or 500 mg/d of the yarrow extract for one year saw reductions in multiple sclerosis relapse rates, volume of lesions, and improved cognitive performance scores compared to placebo.[5]