Plant waste valorisation offers a sustainable approach to extract secondary metabolites with therapeutic, antioxidant, and cosmeceutical potential. Fumaria officinalis (fumitory), a traditionally used medicinal plant, contains various biologically active secondary metabolites, but the influence of different extraction methods on its phytochemical yield, mineral composition, and bioactivity remains underexplored. Four extraction techniques, i.e. maceration (M), heat-assisted extraction (HAE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), were applied to obtain fumitory extracts. The extraction yield, mineral composition, phytochemical functional groups (Fourier Transform Infrared analysis - FT-IR spectroscopy), antimicrobial potential, hemolysis inhibition under thermal and hypotonic stress, and sun protection factor (SPF) were assessed. The extraction technique significantly influenced the extraction yield, which ranged from 17.24% (M) to 37.98% (MAE). Potassium was the most abundant macronutrient (271.56–400.37 g/kg), while all micronutrient concentrations were below 1 g/kg. The FT-IR analysis revealed functional groups typical of phenolics, alkaloids, and proteins, confirming the complex chemical structure of the extracts. All of the extracts exhibited antimicrobial activity against Staphylococcus aureus and Enterococcus faecalis, but not against Gram-negative bacteria or fungi. The UAE and MAE extracts showed superior protection against heat-induced hemolysis (up to 70.4% inhibition at 0.25 mg/ mL), and all the extracts demonstrated moderate, dose-dependent protection in hypotonic conditions. The SPF analysis revealed UV-B absorbance across 290–320 nm, with the UAE extract at 100 µg/mL achieving the highest SPF value (1.66 ± 0.01). The study highlights the significantly influence of the extraction method on the physicochemical and biological properties of F. officinalis extracts. Ultrasound-assisted extraction and MAE were the most effective in obtaining extracts with enhanced bioactivity. These findings support the potential application of fumitory extracts in natural therapeutics and cosmetic formulations. Future work should focus on isolating specific active constituents and evaluating efficacy for pharmaceutical and cosmeceutical applications in terms of wound-healing or anti-aging activities in novel cell models related to disorders, infections, wounds, burns, or skin ageing. https://phaidrabg.bg.ac.rs/o:36661 doi:https://doi.org/10.2298/CPB2502329A eng Ahmoda, Rabiea Ashowen Pirković, Andrea Milošević, Milena Krstic, Aleksandar Erceg, Tamara Marinković, Aleksandar Jovanović, Aleksandra A. Fourier-transform infrared spectra, mineral composition, and biological potential of lyophilized Fumaria officinalis waste extracts volume: 49 number: 2 startpage: 329 endpage: 350 http://creativecommons.org/licenses/by/4.0/legalcode application/pdf 661402 bytes anti-inflammatory potential, antimicrobial activity, fumitory, lyophilisate, sun protection factor 2025 Institute of Botany and Botanical Garden Jevremovac, Belgrade Faculty of Biology, University of Belgrade Fourier-transform infrared spectra, mineral composition, and biological potential of lyophilized Fumaria officinalis waste extracts info:eu-repo/semantics/article