Follitropin beta is a human FSH preparation of rDNA origin, which differs chemically from
natural FSH and follitropin alfa only by slight variances in the composition of the carbohydrate
side chains. In fact, the primary and tertiary structures of both follitropins alfa and beta are
indistinguishable from those of human FSH of natural origin. Furthermore, bioassays and
physiochemical studies indicate that follitropins alfa and beta are indistinguishable from each
other. Therefore, it is not surprising that follitropin beta is approved for the same medical uses
as follitropin alpha.
