Follicle stimulating hormone (FSH) is a gonadotropic hormone produced by the anterior lobe of the mammalian pituitary gland which regulates the normal female and male gamete growth and maturation and normal gonadal steroid production. Deficient endogenous production of FSH is a known cause of infertility and therapeutic preparations of FSH are widely used in the treatment of this condition. In this study, 27 batches of therapeutic rh-FSH preparations were evaluated for their identity and potency before the batch release for use in patients, by using rat ovary weight gain assay as described in the European Pharmacopoeia. The results were calculated by using the Parallel-line assay; COMBISTATS v 4.0 software from EDQM. Based on the findings, it was established that all the 27 batches of rh-FSH were identified to be Follicle Stimulating Hormone and their estimated potencies were found to be within the specification limits as per the European Pharmacopeia.