ABSTRACT As palatability of medical formulas has been documented as unpleasant, new options are required to improve acceptance and adherence in people with inborn errors of metabolism (IEM). Miracle fruit (Synsepalum dulcificum) has a glycoprotein named miraculin that transforms a sour, bitter taste such as the one found in metabolic formula, into a sweet perception. The objective of this work is to analyze the response in the taste perception of metabolic formula with the use of the miraculin tablets in patients with IEM and healthy adults. To test this hypothesis a prospective, longitudinal, quasi-experimental, analytical study was performed. Patients with IEM and healthy adults were recruited. All participants assessed 3 different liquids (lemon, apple cider vinegar and metabolic formula) before and after the administration of miraculin tablets and completed a questionnaire. The sensory responses were evaluated using hedonic scales, analyzed with nonparametric tests for paired data. Seven patients with IEM and 14 healthy subjects were included. After miraculin intake 57% of patients (Z ≤ -1.89 p= 0.059) and healthy adults (Z≤ -2.31 p= 0.021) had a positive change in their taste perception. The absolute frequency of patients who did not like the metabolic formula decreased from 4 to 1, and in patients who liked it or loved, it increased from 0 to 2 and from 0 to 1 respectively; the frequency of patients who perceived the metabolic formula as indifferent or hated it, did not change. Response in taste perception had a positive change of 57% in both groups. The use of miraculin tablets may improve palatability of metabolic formula.