The Piloselle and the legend of the falcon with the piercing gaze

A legend claims that a falcon feeds on mouse-ear juice in order to improve its eyesight. Hierakon , in which we guess the Latin name of the piloselle; Hieracium , was already the Greek name for several Chicoraceae, but it also contains Hierax , “falcon”. The pilosella has therefore been given the name of Hieracium , “without anyone seeing any explanation apart from popular legends “.

A little history

The choice of the falcon is perhaps not so trivial as we know how much this bird has a piercing sight. All this briefly linked us to Antiquity, but at that distant time, there is no question of the piloselle; it is not mentioned by any of the ancient ancient authors. It is only in the twelfth century that we encounter it for the first time; recorded by the hand of this great lady that was Hildegard . She then gives him the name of Musore.

Hildegarde explains to us that the piloselle makes it possible to reduce the bad humors accumulated in the body . No doubt it refers to the diuretic and depurative effects of the hawkweed, driving chlorides, urea and other toxins out of the body.

The very name of the piloselle emanates from the late Middle Ages, and comes from the fact that, as Gaspard Bauhin (1560-1624) points out, the piloselle is copiously hairy. It is described in the Hortus sanitatis of 1485 as well as in the Herbarius of 1536.

In 1554, Matthiole wrote that “physicians have learned that it constitutes a remedy for dysentery and metrorrhagia. In addition, macerated in slightly harsh wine, it causes wounds, both internal and external, to close: it is of great help against vomiting of bile, spitting up blood, enteritis, intestinal hernias and all fractures, especially of the skull. There is not even a lack of physicians, especially contemporary ones, who recommend it in affections of the liver and spleen and in the beginnings of dropsy. It is usefully added to drinks in cases of internal wounds and to plasters and vulnerary balms, because not only does it heal recent wounds, but it also heals stubborn ulcers”.

What are the main pharmacological properties of Piloselle?

Renal activity:

  • Bacteriostatic properties:

In vitro tests performed in the late 1940s demonstrated that free umbelliferone exerts bacteriostatic activity . This coumarin is capable of inhibiting bacterial colonies such as Brucella ( abortus and melitensi s) as well as mainly Salmonella typhimurium , but also Staphylococcus aureus and Escherichia coli . Isotein 4′-O-β-D-glucopyranoside, a flavonoid isolated from the methanolic extract of the aerial parts of Hieracium pilosella , inhibits the growth of Pseudomonas aeruginosa. This activity is potentiated in particular by the presence of acid-phenols, which are antibacterial .

  • Detoxifying and aquaretic properties:

This traditionally recognized activity would be linked to the presence of flavonoids, which promote the elimination of urea, uric acid, and chlorides . The diuretic action of mouse-ear hawkweed is also linked to its richness in inulin. This compound, a mixture of polysaccharides and oligosaccharides consisting of fructose polymers ending in an α-D-glucose linked to this chain, is a fructan which increases the osmotic pressure at the level of the renal glomerulus. This action leads to greater elimination of the water filtered by the latter, and therefore causes a diuretic effect , which also helps relieve inflammation of the urinary tract .

  • Activity on glomerular filtration:

Hawkweed increases vasodilation of the renal parenchyma , thereby improving glomerular filtration rate.

Hepatodigestive activity:

  • Choleretic and hypocholesterolemic properties:

Umbelliferone also exerts a choleretic activity , without cholagogue effect. The action of acid-phenols associated with umbelliferone on the quality of bile explains the anti-hypocholesterolemic action of the mouse-ear. It also has a spasmolytic activity at the level of the sphincter of Oddi.

  • Intestinal properties:

This action is in fact due to the astringent properties of its tannins, the piloselle exerts an antidiarrheal and intestinal healing activity .

Antioxidant, anti-inflammatory and antiproliferative properties:

Generally speaking, polyphenolic compounds, such as those contained in mouse-ear hawkweed, have shown antioxidant, anti-inflammatory, and cardioprotective properties , as well as antimicrobial, antimutagenic, and antiproliferative properties . Significant antioxidant activity was confirmed for chlorogenic acid, apigenin-7-O-glucoside and umbelliferone contained in mouse-ear.

Studies from 2011 reported the antioxidant effects of a new flavonoid isolated from Hieracium pilosella (isoetin 4′-O-β-D-glucopyranoside). Besides strong free radical scavenging activity , this compound showed significant antiproliferative action against a colon carcinoma cell line.

Are there any precautions for use concerning the Piloselle?


  • A medical opinion is ultimately advised in case of use of piloselle during pregnancy or breastfeeding.

Precautions for use:

  • To ensure an increase in the amount of urine, adequate fluid intake is necessary during treatment.
  • In the context of the use of the piloselle in self-medication, if the symptoms worsen during the use of the plant, a doctor or a qualified health professional should be consulted. Similarly, the occurrence of fever, dysuria, spasms or blood in the urine requires medical consultation.
  • Do not use pilosella, a diuretic plant, during an attack of renal colic. The plant can be used immediately after the crisis.
  • Hawkweed is not suitable for the treatment of possible fluid retention due to kidney failure or heart failure. The occurrence of edema requires a medical consultation.

How to take Piloselle and at what dosage?

Dry form:

Liquid form:

Medical bibliographic sources and clinical trials :


Clementine. M.
Writer of scientific articles
Naturopath – Aromatherapist / Herbalist – Phytotherapist
Consultant in clinical phyto-aromatherapy and Ethnomedecine

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