Is oak toxic?
No, oak is not a toxic plant. However, it is rich in tannins and phenolic acids (20%), which are contraindicated in some cases.
Tannins are chemical compounds which, in high doses, can cause intestinal disorders and irritation of the gastrointestinal mucosa.
Because of these components, oak should be used with caution, especially internally.
* More information on oak side effects
Oak toxicity and hazards
Oak leaves and fruits (acorns)
Toxic principles: rich in tannins
The major toxicity of oak is given by the high tannin content of the bark (up to 20%), which is present in smaller proportions in the leaves and fruits (acorns).
The tannins are irritating to the intestinal mucosa, so they can cause vomiting and even digestive ulcers. Tannins can block intestinal secretions and alter the bacterial flora, leading to constipation.
It is recommended, therefore, to use preparations for internal use only under supervision of the physician and never exceed the dose recommended by the specialist. These preparations should be taken after meals to prevent digestive problems, while respecting the patterned dose.
Oak should never be taken in case of gastritis or digestive ulcers. Treatments for internal use should not be prolonged for more than 4 days.
External use application should not continue more than 15 to 20 days. Essential oil baths should not be performed when the patient has infections, fever or heart problems.
More information on oak.