Introduction: Inula helenium L. is a medicinal plant widely used in traditional Mongolian and Tibetan medicine. Its roots and rhizomes contain active compounds, including sesquiterpene lactones (alantolactone and isoalantolactone), inulin, flavonoids, and essential oils, with anti-inflammatory, antimicrobial, and immunomodulatory properties. This study evaluates the quality of Inula helenium L. roots and quantifies their key active compounds in accordance with pharmacopoeial standards. Methods: The roots of Inula helenium L. cultivated in the Medicinal Plant Botanical Garden of Monos Group were used as raw material. Physicochemical parameters, including moisture, total ash, acid-insoluble ash, and extractive values, were determined according to pharmacopoeial methods. Qualitative analysis was carried out using color reactions for polysaccharides and thin-layer chromatography for the identification of sesquiterpene lactones. Quantitative analysis was performed using spectrophotometry for total polysaccharides and high-performance liquid chromatography (HPLC) for the determination of alantolactone and isoalantolactone. Conclusion The physicochemical parameters of Inula helenium L. root were standardized, with total inulin content determined as 47.13±0.45%, alantolactone as 1.41±0.02%, and isoalantolactone as 1.33±0.02%. Analytical methods for inulin, alantolactone, and isoalantolactone were validated according to ICH Q2(R2) guidelines, confirming the possibility of updating the MNS standard or developing a manufacturer’s pharmacopoeial monograph based on these validated methods.