The medicinal part of the oak is the leaves and nuts. Some parts of the oak tree are poisonous to cattle because the oak contains a large amount of tannic acid. The tannic acid is where the oak gets its medicinal properties. The tannins help to cure viral infections and diarrhea. It is also known to help quell certain symptoms of eczema and inflammation. Oak can be found in tea form.
The medicinal parts are the dried bark of the young branches and the lateral shoots, the dried bark of the trunk and branches, the dried leaves of various oak species, and the seed kernels without the seed coats.
Flower and Fruit
The flowers are reddish brown and monoecious. The male flowers consist of a 5-part perigone with 6 to 10 stamens that appear in small groups in limp, hanging catkins. The female flowers, solitary or in groups of up to 5, appear in an involucre, which clasps the base of the fruit and later becomes bowl-shaped. The fruit is solitary or in groups of up to 5 on a shared glabrous or sparsely pubescent stem. They are oblong-ovate, acuminate, and enclosed in the cupule.
Leaves, Stem, and Root
The tree is about 50 m high with a broad, irregular, heavily branched crown and a trunk which divides into gnarled, strong, bent branches. The bark is deeply fissured, thick, and grey-brown. The leaves are short-petioled, almost sessile, oblong-obovate, almost lobed, usually cordate, or polled at the base.
The tree is widespread in Europe, Asia Minor, and the Caucasus region.
Oak bark consists of the dried bark of young branches and saplings of Quercus robur and/or Quercus petraea, harvested in the spring, as well as their preparations. Oak bark is harvested from March to April. The trees fall every 10 years. The bark is dried rapidly.
Common Oak, English Oak, Pedunculate Oak, Tanner's Bark
Actions & Pharmacology
Catechin tannins: oligomeric proanthocyanidins
Ellagitannins: (including castalagin, pedunculagin, vesvalagin, 2,3-(S)-hexahydroxy diphenoyl glucose), flavano-ellagitannins (acutissimins A and B, eugenigrandin, guajavacin B, stenophyllanin C)
Monomeric and dimeric catechins and leucocyanidins
Tannins (12 to 16%)
The drug, which contains tannins, is astringent, antiphlogistic, antiviral and anthelmintic.
Indications & Usage
Approved by Commission E:
- Inflammation of the mouth and pharynx
- Inflammation of the skin
Oak is used internally for nonspecific diarrhea. In smaller doses it is used as a stomach tonic. The drug is used externally for inflammatory skin diseases and inflammation of the mouth and throat.
In folk medicine, Oak is used for inflammation of the genital and anal area, suppurating eczema, hyperhydrosis, intertrigo, and as an adjuvant treatment of chilblains. Oak is also used in folk medicine internally for hemorrhagic stool, nonmenstrual uterine bleeding, hemoptysis, and chronic inflammation of the gastrointestinal tract. External uses include hemorrhoid bleeding, varicose veins, uterine bleeding, vaginal discharge (washes/douches), rashes, chronic, itching, scaly and suppurating eczema, and eye inflammations.
Whole-body baths are contraindicated with large-area weeping eczemas and skin injuries, with feverish and infectious illnesses, with cardiac insufficiency in stages III and IV (NYHA), and with hypertonia in stage IV (WHO).
Precautions & Adverse Reactions
No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages. Internal administration could lead to digestive complaints because of the secretion-inhibiting effect of the tannins.
The absorption of alkaloids and other alkaline drugs may be reduced or inhibited.
Mode of Administration
Oak is available as whole, crude, and powdered drug form, as a bath additive and in compounded preparations. It is also available in solid pharmaceutical form for oral intake.
Tea – 1 gm finely cut or coarse powdered drug is put in cold water, rapidly boiled and strained after some time (1 teaspoon corresponds to 3 g drug).
Bath additive – 5 g drug is boiled with 1 Liter water and added to the full or hip bath.
- Internally – 3 g of drug; Tea: 1 cup 3 times a day.
- Externally – Rinses/gargles: boil 2 dessertspoons finely cut drug with 3 cups water.
- Bath additive – duration: 20 minutes at 32 to 37º C.
Should be tightly sealed and protected from light.