modified hormones or fragments of hormones are useful in producing antibodies when administered to an animal . said antibodies in turn cause neutralization of endogenous natural protein hormones . the modification may be accomplished by attaching various kinds of modifying groups to the hormone or fragment . modification may , for example , be achieved by chemically coupling diazosulfanilic acid groups to the hormone or fragment . the protein hormones to which this procedure can be applied are mammalian protein reproductive hormones such as , for example , follicle stimulating hormone , or human chorionic gonadotropin . these modified hormone or fragment may be administered to animals for the purpose of contraception , abortion , or treatment of hormone related disease states and disorders .