Introduction: Cordyceps sinensis, a renowned herbal medicine, contains pharmacologically beneficial compounds, including γ-aminobutyric acid (GABA), necessitating efficient analytical methods for quality assessment. This study aims to develop a rapid, cost-effective, and ecofriendly liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for GABA quantification in Cordyceps sinensis and its related species. The objective is to enhance the quality control standards within the Cordyceps sinensis industry and for those of its related species. Methods: The study innovated a swift analytical procedure. Optimal conditions were determined through systematic evaluations of extraction solvents, durations, and chromatographic settings, prioritizing speed and solvent minimization. Results: The proposed LC–MS/MS method achieved precise quantification of GABA in a reduced time frame and significantly lowered solvent consumption, enhancing method efficiency by 22-fold compared to reported LC methods. The method exhibited robustness and scored the highest blue applicability grade index score, underscoring its suitability for academic and industrial applicaition. Conclusion: The validated LC–MS/MS approach offers a sustainable avenue for the rapid and accurate measurement of GABA in Cordyceps sinensis and its related species, improving the quality control process and ensuring product authenticity. This method stands out as a model for green analytical chemistry, propelling forward the eco-friendly analytical evaluation of health-related compounds.

Development and Validation of an Eco-Friendly Liquid Chromatography–Tandem Mass Spectrometry Method for Rapid Quantification of Γ-Aminobutyric Acid in Cordyceps Sinensis and Its Related Species