Unfounded skepticism relating to biosimilars, arising from the assertion that they are not molecularly identical to their original counterpart, fails to acknowledge that no biological medicine, including Gonal-f® (from Merck Serono) is identical to itself. Molecular differences between the biosimilar and the reference medicines are irrelevant and clinically undetectable as long as they are contained within the accepted variability in the original medicine. Accordingly, the minor differences in 'ongoing pregnancy rate' and 'live birth' rate reported in a recent meta-analysis of biosimilars and Gonal-f® are probably driven by product-unrelated factors, notwithstanding the fact that of the four products under analysis, only Ovaleap® (from Theramex) and Bemfola® (from Gedeon Richter Plc) can unambiguously be considered to be biosimilars. The EU biosimilars model has proven successful, but given the distrust in biosimilars that is built on a biased foundation, the full promise of rFSH alfa biosimilars for reproductive medicine patients is unlikely to be fulfilled {AuQ: Edit OK?}. Teaser: {AuQ: Please provide the missing teaser.}.