In women with infertility due to anovulation, the main purpose of ovulation induction (OI) consists in inducing the mono or bifollicular and the subsequent ovulation in order to achieve pregnancy. The availability of recombinant gonadotropins obtained using genetically engineered techniques has meant a decisive and clear pharmacological advancement. Use of recombinant human follicle stimulating hormone (r-hFSH) offers a greater effectiveness (greater number of follicles/ ovocytes and a higher pregnancy rate) and efficiency (fewer number of blisters, fewer stimulation days; fewer number of cancellations and complications) in programmed coitus and artificial insemination like in-vitro fertilisation (IVF)/intra cytoplasmic sperm injection (ICSI) techniques. Further advances in obtaining better products for ovarian stimulation has led to production of a recombinant FSH (follitropin alpha) filled by mass preparation. This hormone becomes the most consistent and precise gonadotropin due to improvements in its quantification process.