Abstract: Non-hormonal contraception compositions and methods for contraception are provided. One embodiment provides an antibody or an antigen binding fragment thereof that specifically binds to one or more sperm antigens and inhibits the ability of anti-body-bound sperm to fertilize an egg. Typically, the antibody is a monoclonal antibody, for example a human or humanized monoclonal antibody. In one embodiment, the antibody or antigen binding fragment thereof specifically binds to CD52g expressed on vertebrate, for example human, sperm cells and inhibits, blocks, or reduces the ability of the antibody-bound sperm to fertilize an egg. In one embodiment the antibody contains a membrane anchor. The membrane anchor can contain transmembrane domains, glycosylphosphatidylinositol anchors, or myristoylation motifs.