After the use of a dry extract from birch leaves some adverse reactions, but non-serious, such as skin disorders (itching, rash), gastro-intestinal system disorders (diarrhoea, nausea, stomach upset, etc), metabolic and nutritional disorders (oedema of the legs), and general disorders (allergic reaction with dizziness, nausea, swelling of nasal mucous membrane, peripheral oedema) have been reported [19].