Among feminist philosophers, there are two lines of argument that sexist values are illegitimate in science, focusing on epistemic or ethical problems. This article supports a third framework, elucidating how value-laden science can enable epistemic oppression. My analysis demonstrates how purported knowledge laden with sexist values can compromise epistemic autonomy and contribute to paternalism and misogyny. I exemplify these epistemic wrongs with a case study of the morning-after pill during its 2006 switch to over-the-counter availability and its new drug label (...) from the US Food and Drug Administration that it “may prevent implantation.” Antiabortion science advisers created this label to protect zygotes based on debated value judgments that were later concealed. This zygote-centric knowledge enabled them to shape potential users by instructing “good mothers” that they ought to protect zygotes and punishing “bad mothers” by refusing their requests for the drug. Therefore, I argue that the sexist values and gender norms of antiabortionists that prioritize zygotic health are illegitimate in this context because they cause epistemic injustices and perpetuate epistemic oppression. Furthermore, I advocate against blanket protections for the “right to conscience” and “religious freedom” of healthcare providers because they reinforce the epistemic oppression of women, especially those on the margins.Content Warning: This article discusses sexual assault and refusals to provide contraception to patients, including survivors. (shrink)