Summary.

The aim of this study is to assess the health claims of proclaimed food supplements containing L-tyrosine according to regulatory requirements on the basis of label’s information of 21 food supplements, containing L-tyrosine available in the Bulgarian marketplace, 89 food supplements, containing L-tyrosine available in the USA marketplace, and current scientific information, analysis of the optimum conditions for L-tyrosine administration, possible interactions with drugs, foods and food supplements. Of the investigated food supplements two products available in the Bulgarian marketplace have impermissible health claims according to Bulgarian legislation to treat diseases: narcolepsy and depression. The present research confirms the statement that the application of food supplements containing L-tyrosine could be favorable for the health but physicians, pharmacists and other health care professionals should be warned about the permissible claims and the precautions and follow the daily intake of amino acids including Ltyrosine and L-phenylalanine obtained by food.