Oak Bark (Red)

Oak bark (Quercus robur), also known as white oak, comes from the bark of a tree in the Fagaceae family. The bark from the oak tree is the only part that is used medicinally; oak bark is harvested from March to April. White oak bark is recognized as an herbal remedy that is generally safe, being listed on the GRAS list—meaning “Generally recognized to be safe” by the FDA. The German Commission E has approved the use of oak bark for the treatment of diarrhea, and it has been listed on the US Pharmacopoeia since 1916 for its astringent and antiseptic qualities.

Other names for oak bark include:

Common oak
Corteza de roble
Durmast oak
English oak
Pedunculate oak
Quercus sp. including alba, cortex, pedunculata, petraea, and sessiliflora
Sessile oak
Stave oak
Stone oak
Tanner's bark or Tanner's oak
Health Benefits
There are hundreds of various tree species with a common name of oak, but the genus Quercus (the Latin name for oak tree) includes deciduous trees or live oaks that are native to the northern hemisphere. In ancient folklore, the oak Quercus was known as the most sacred of all plants.

Oak bark is known to have many health-promoting properties, including up to 20% tannins. It’s been used to treat a wide range of maladies including colds and flu, eczema, varicose veins, and more.

In herbal medicine, oak bark is known for its strong astringent properties and for treating infections of the mouth, bleeding gums, acute diarrhea, skin conditions, wounds, burns, and cuts.

Other conditions that oak bark is commonly used for include:

Acute diarrhea
Pharyngitis (sore throat)
Mouth sores and bleeding gums
Colds, coughs, and bronchitis
Loss of appetite
Digestive disorders
Pain and inflammation

There is a lack of adequate human medical research studies (double-blind placebo studies) to back the claims of safety and effectiveness for treating these conditions.

Health Promoting Properties
The healing properties of oak bark thought to promote health benefits include:

Anodyne: A substance with painkilling properties
Astringent: A property that causes the constriction of cells and body tissues to help treat abrasions, bleeding, and other conditions
Depurative: Herbs that are considered to have purifying and detoxifying effects
Emmenagogue: A substance that stimulates or increases menstrual flow
Styptic: A substance capable of stopping bleeding when applied to a wound (commonly used in styptic pencils)
The high concentration of tannins in oak bark is thought to promote very strong astringent properties;1 this prompted health professionals in Germany to consider oak bark for the treatment of skin conditions such as:

Skin irritation
Itchy patches of skin
Inflamed skin
Infected wounds
Staph infections
Bleeding cuts or wounds
Herpes zoster (shingles) lesions
HCA Healthcare reports that oak bark may have cancer preventative properties, but using oak bark for cancer treatment will very likely not occur in the near future. This is because of the time that it takes to perform human studies that show enough evidence of clinical benefit and safety.

According to Whole Health Chicago, a commercial preparation of oak bark called “Litiax” is available in Europe as a diuretic (water pill) that also lowers pain and inflammation. Litiax’s diuretic effect has been used in Europe to prevent kidney stones from forming (in those who are prone to kidney stones).

However, some medical experts report that oak bark is contraindicated in people with kidney stones. HCA Healthcare reports that there is “very weak evidence (too weak to be relied upon at all),” when it comes to using oak bark to treat kidney stones. The medical research is in the preliminary stages and there is not enough data to recommend the safety or effectiveness in the use of oak bark for preventing kidney stones.

It’s best to consult with the healthcare provider before using any type of medicinal herbal preparation (including oak bark); this is particularly true for those with health conditions, including kidney stones and liver conditions.

Medical researchers are working to find out if oak bark is effective at lowering cholesterol, but there is not enough current clinical research evidence to support these claims.

How it Works
The strongest healing component in oak bark is its tannins.1 Tannins are a yellowish or brownish, bitter-tasting organic substance found in the bark and galls (abnormal growths found on trees, shrubs, and foliage) of many plants.

Tannins have astringent and antiseptic properties (considered useful in treating wounds and cuts). Tannins are also thought to speed up blood clotting and stabilize blood pressure and are thought to help lessen symptoms of acute (a severe condition that comes on quickly) diarrhea.

Other potentially active components of oak bark include saponins. Saponins are thought to assist in the removal of excess fats in the body, binding with the fats in the digestive tract and helping to break them down; this may help to lower the absorption rate of cholesterol.

But saponins are not very well understood in the medical research world. More research is needed to prove that saponins are capable of lowering cholesterol.1

Saponins are also thought to be useful as an expectorant (an agent that helps enhance coughing up phlegm and mucus). But again, there is no definitive medical research evidence to prove this.

Preliminary studies have been conducted to determine the effectiveness of a topical (on the skin) oak bark ointment on a resistant form of staph infection, called methicillin-resistant Staphylococcus aureus, in wounds and in healing burns.

The study results indicated that “The oak bark formulation can enhance the migration of epidermal cells to accelerate healing.” The study authors add that more studies are needed to conclusively deem oak bark as safe and effective in the treatment for burns and staph infections.2

Possible Side Effects