BACKGROUND Based on personal observations of dermatologists, nutritionists and patients, a new problem emerges in the gyms: development and exacerbation of acne in users of whey protein, which is a protein derived from cow's milk. Whey Protein extract contains growth factors that may be related to acne. Its purity and composition are not fully known and there is no scientific research on its potential to cause acne. OBJECTIVES Assess the relationship between the use of proteincalorie supplements and onset or exacerbation of acne vulgaris in young adults in the city of João Pessoa. METHODS Descriptive observational study conducted in gyms and in a dermatology clinic. Each participant was examined for acne on three occasions and followed for 60 days. RESULTS 30 patients were examined. Onset or exacerbation of acneiform lesions were observed (p <0.0005). The effect was more prominent in females and in individuals without current acne and no family history of acne. CONCLUSION This study showed the onset of acne with the progressive use of protein-calorie supplementation, in a two-month period. It is suggested that this type of supplementation be discouraged.