A a method for obtaining an extract prepared from cranberry (genus Vaccinium macrocarpon and/or Vaccinium oxycoccus) marc, with a view to obtaining a product that, provided in various galenical forms or other, has, owing to the high concentration of proanthocyanidins, in particular type A proanthocyanidins, therein, many therapeutic qualities and properties that can be exploited in particular in the field of dental care and prevention and oral hygiene, and also in the field of the prevention of viral or bacterial infections of the oropharynx in humans and animals. It also relates to this extract and to uses thereof.