Objective was to to analyze the protein components of extracts of diagnostic allergens made in Ukraine in order to determine the next steps for their standardization. Electrophoresis in polyacrylamide gel was used to obtain electrophoregrams of Acarus siro, Dermatophagoides farinae, Dermatophagoides pteronyssinus, Alnus glutinosa, Betula pendula, Carpinus betulus, Ambrosia artemisiifolia, Artemisia absinthium, Dactylis glomerata, Festuca pratensis, Helianthus annuus, Lolium perenle, Poa pratensis, Secale cereale, Zea mays, cat hair, dog hair, sheep allergens, and allergen of feather pillows. The official site for the systematic nomenclature of allergens approved by the World Health Organization and the International Union of Immunological Societies was used to identify allergenic components. Analysis of the data shows that 14 out of 20 (70%) of our studied allergen extracts contain ballast non-allergenic protein. In some cases (for example, for mite allergens, ragweed), this non-allergenic protein is able to mask the major protein components of allergens. For most of the studied extracts, the major components were clearly detected. Most of the studied extracts, in addition to major, also contained minor components, forming a "cocktail" of each individual allergen. However, as we mentioned earlier, non-allergenic ballast proteins can be a serious problem in the existing scheme of standardization of extracts by protein units of nitrogen, because such standardization actually calculates the total amount of protein per unit volume of extract.