Cat’s claw (Uncaria tomentosa) is a huge liana that grows in the jungles of South America and Mesoamerica. It stands out for containing high concentrations of oxindolic alkaloids and phenolic compounds, especially pro–anthocyanidins. This explains its use in traditional medicine as an anti–inflammatory and antioxidant agent. The present study focused on the latter characteristic. The objective is to enhance it with citric acid, a very common food additive. For this purpose, a gradient of citric acid concentrations was established and the antioxidant profile of aqueous leaf and bark extracts was evaluated with the following assays: Folin–Ciocalteu, DPPH, FRAP and ABTS. Which revealed that the concentration of citric acid and antioxidant capacity are directly proportional variables. The statistical method also confirmed that the difference is significant. On the other hand, citric acid produced better results in peel extracts, although leaf extracts yielded higher values of antioxidant activity. Keywords: Uncaria tomentosa, citric acid, potentiation, antioxidant activity, Folin–Ciocalteu, DPPH, FRAP, ABTS.