Comparative analysis of the primary structure of recombinant human follicle-stimulating hormone (r-hFSH) in samples of follitropin alpha biosimilar (FAB) preparation and the reference drug Gonal-F showed they were identical while spectral analysis of their secondary and tertiary structures indicated they were bioequivalent. Analytical results for N-glycans and sialic acids revealed that the main glycan structures were similar and the distributions of the main forms of sialic acids in the compared samples differed insignificantly. Results of in vitro and in vivo biological activity testing confirmed that FAB and Gonal-F were equivalent with respect to WHO standards. Comparative testing of the acute and subacute toxicity did not reveal significant differences between the two drugs and also confirmed they were identical. Thus, the investigation proved that FAB and the reference drug were equivalent with respect to the main physicochemical, pharmacodynamic, and toxicological characteristics.