Graphycal Abstract:Melissa officinalis L. and Urtica dioica L. were evaluated for their phytochemical composition and antioxidant and anti-lithiatic activities. LC-MS/MS analysis showed that M. officinalis contained a more diverse profile, especially flavonoids and phenolic acids enriched in the ethyl acetate fraction, while U. dioica demonstrated a simpler composition dominated by myricetin, riboflavin, sinapic acid, catechin, and β-carotene in its aqueous fraction. M. officinalis ethyl acetate extract showed the strongest antioxidant capacity in DPPH, ABTS, and FRAP assays. Its aqueous extract also exhibited notable anti-lithiatic activity, inhibiting calcium oxalate crystal formation by 87.12% at 2 mg/mL.