The purpose of the current phase I study was to establish bioequivalence, safety, and tolerance of single 300 IU subcutaneous dose of primapur in comparison to that of reference follitropin alfa preparation (gonal-f) in healthy young female volunteers. No significant differences in pharmacokinetic parameters between primapur and gonal-f were detected for AUC0-192 93.31% (90% confidence interval [CI]: 87.25-99.79%) and Cmax 87.93% (90% CI: 82.85-93.33%). Both primapur and gonal-f were well tolerated, with no serious adverse events or those leading to discontinuation of treatment course. The results of this study indicate that a single dose of primapur solution for subcutaneous injection exhibits pharmacokinetic and safety profiles comparable to those of original gonal-f in healthy young women.