The aim of controlled ovarian hyperstymulation in in vitro fertilisation is to obtain mature oocytes with high reproductive capability. Currently, among various stimulation protocols with the use of GnRH agonist, the most popular is the so-called „long protocol” in which aGnRH is pre-administered in order to desensitize the pituitary. The choice of a particular type of exogenous gonadotrophin (HMG vs rFSH) applied in stimulation remains a controversial issue. The metaanalyses carried out so far have not been able to prove the superiority of any of the available medications. Recently, in a number of sites in several countries a prospective randomized research was carried out. The researchers focused on Menopur, which contains FSH and LH and Gonal F (recombined FSH). The research has proved a positive (but not significant) influence of LH in Menopur on the pregnancy rate obtained during classical IVF (PR 27%), compared to stimulation with rFSH alone (PR 22%).