Herbal mixtures are gaining popularity due to their potential health benefits. This study aimed to evaluate and compare the antioxidant activity, phenolic composition and bioactive properties of four herbal mixtures with a predominant herb produced by a company in northern Portugal: "Flavors of Health" - Mentha piperita (35%) (A), "Detox Mix" - Hypericum perforatum (44%) (B), "Salad Mix" - Foeniculum vulgare (23%) (C), and "Grilling Mix" - Laurus nobilis (31%) (D). Infusions were prepared from 1 g of dry sample per 200 ml of distilled water, filtered, frozen (−20 °C), and lyophilized. Phenolic composition was analyzed using HPLC/DAD-ESI/MS, and bioactivity was assessed through lipid peroxidation inhibition (TBARS) and oxidative hemolysis inhibition (OxHLIA). Fifty-nine phenolic compounds were identified, including 19 phenolic acids and 40 flavonoids. Mixtures A and B showed the highest total phenolic acids content, with 5.99±0.063 and 5.66±0.051 µg/ml, respectively. Even though mixtures A e C presented the highest number of flavonoids (16 and 17, respectively), sample B was the richest in total flavonoids concentration (11.87±0.127 µg/ml) with peak 25 (Eridictyol-O-rutinoside 5.542±0.07 µg/ml) being the most relevant. Rosmarinic acid cis (peak 54) was the most significant phenolic acid in all extracts, with concentrations of 1.917±0.027 to 2.685±0.057 µg/ml. Mixtures D and A had the highest concentrations of this acid (2.685±0.057 and 1.917±0.027 µg/ml, respectively). In the TBARS assay, mixture A exhibited the highest antioxidant activity (EC50 = 8.6±0.4 µg/ml), and it also showed the greatest potential in the OxHLIA assay (EC50 = 0.143±0.004 µg/ml). Considering only the antioxidant properties of the mixtures, "Flavors of Health" is the most consistent sample. On the other hand, when examining the phenolic composition and bioactive properties, samples B and D were identified as the richest. Thus, this study contributes to health enhancement, fostering consumer trust and reinforcing the industry's commitment to well-being.