INTRODUCTION: The Acquired Immunodeficiency Syndrome (AIDS) is an important global public health problem. Since 2015, the World Health Organization has recommended that healthy people, but at risk of exposure to HIV, make use of Pre-Exposure Prophylaxis to HIV (PrEP), commercially known as Truvada. Despite having side effects, they tend to disappear within three months, but this impairs adherence to treatment. OBJECTIVES: The objective of the study is to evaluate the relationship between the changes felt and reported by patients using PrEP. MATERIALS AND METHOD: This observational and analytical study had a group of 47 participants, who were evaluated before starting the use of PrEP (T0) and, in two moments after the beginning of the medication, T1 and T2, referring to the second and third drug dispensing, respectively. Notes were made of the patient’s report on possible oral and systemic changes felt by him after starting PrEP use. RESULTS: The results took place over 120 days. A total of 32 participants presented oral alterations before the start of medication (T0), most of them being linea alba and traumatic ulcerations. Of the 30 participants in T1, 10 had oral alterations and 20 had systemic alterations, the most frequent being dry mouth, nausea, vomiting and diarrhea, respectively. In T2, of the 17 participants, oral alterations were reported by 10 patients and systemic alterations by 11 patients, with a higher frequency of mucosa and skin dryness, respectively. FINAL CONSIDERATIONS: In the present study, although the side effects of PrEP were temporary, there was a sample loss during the follow-up period, which was greater in the first return of the patients.
