OBJECTIVE: The aim of this study was to evaluate potential skin sensitization andcollagen synthesis of rats receiving proteoglycan (PG) serum. MATERIAL AND METHODS: Eighteen rats were randomly divided into 3 groupsequally and assigned to receive 1 ml of serum base (control), 1% PG and 2% PG appliedto skin. Histological analysis was evaluated for potential skin sensitization and collagensynthesis on days 7, 14, 21and 28. RESULTS: Histological analysis showed that 1% PG and 2% PG acceleratedcollagen synthesis. The evaluation of potential skin sensitization, on day 7, 14, 21 and28 of rat applied with 1% PG and 2% PG were not significantly different whencompared to the control group. Keywords: proteoglycans, collagen synthesis, potential skin sensitization, Trichopoduspectoralis CONCLUSION: This study demonstrated that PG serum accelerated collagensynthesis and low potential skin sensitization.