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Background: One of the most challenging aspects related to Covid-19 is to establish which are the characteristics that may explain clinical variability among patients. To achieve this objective, we compared serum metabolomic profiles of asymptomatic SARS-CoV-2 carriers to patients affected by mild and severe symptoms.Methods: All subjects underwent quantitative assays for anti-SARS-CoV-2 antibody detection. Serum samples for metabolomic analysis were obtained from 109 healthy controls; 15 seroconverted, asymptomatic subjects (AS); 16 Covid-19 patients with mild symptomatology (MI) and 12 patients with severe symptomatology (SE). Metabolites were identified using Mass Spectrometry coupled to Gas Chromatography. Uni- and multivariate approaches were used to select the most relevant metabolites. Results: Anti SARS-CoV-2 IgG showed an increasing trend from controls to asymptomatic and mild severity patients. Tyrosine, phenylalanine, acetoacetate and fumarate showed a decreased concentration in MI compared to both CTRL and AS subjects; on the contrary, mandelic acid showed an increased concertation. The shortest route among these metabolites resulted the Tyrosine metabolism. Aspartic acid, alanine, isoleucine, valine and proline were decreased in MI patients, while methionine and oxo-leucine resulted increased. An increased concertation of fatty acids lauric and myristic acid, phospholipids (phosphatidyl myo-inositol and lyso-phosphatidyl inositol) and histamine were recorded in MI and SE. Conclusion: The reported metabolite levels could be explained by an increase production of L-DOPA, resulting in a following increased production of noradrenaline and adrenaline that could, at least partially, explain the different clinical presentation of the infection.