How reliable is the labeling of a commercial phytosteroid product? A 12-week randomized double-blind training study

This study demonstrated that the prescribed resistance training protocol resulted in significant anabolic and performance-enhancing effects that did not differ between groups. The lack of group-specific differences suggests that the tested phytosteroid supplement did not provide additional benefits. The significant discrepancy between the claimed and actual 20E and DSG concentration resulted in the lack of biological activity in C2C12 cells and likely contributed to the absence of measurable group-specific effects. To enhance the reliability of future phytosteroid research, we strongly recommend: (1) verification of active compound concentrations in supplements, its actual content and absence of potential contamination with prohibited substances, (2) confirmation of their biological activity using <i>in vitro</i> models. Implementing these measures will help to minimize inconsistencies and enhance the reliability of future studies on phytosteroids.