Recent explosive growth in environmental and climate-related marketing claims by business firms has raised concerns about the truthfulness of these claims. Critics argue (or at least question whether) such claims constitute greenwashing, which refers to a set of deceptive marketing practices in which an entity publicly misrepresents or exaggerates the positive environmental impact of a product, a service, or the entity itself. The extent to which greenwashing can be regulated consistent with the First Amendment raises thorny doctrinal questions that have bedeviled both courts and scholars. The answers to these questions have implications far beyond environmental marketing claims. This Essay is the first to offer both doctrinal clarity and a normative approach to understanding how the First Amendment should tackle issues at the nexus of science, politics, and markets. It contends that the analysis should be driven by the normative values underlying the protection of speech under the First Amendment in the disparate doctrines that govern these three arenas. When listeners are epistemically dependent for information on commercial speakers, regulation of such speech for truthfulness is consistent with the First Amendment and subject to the laxer review of the commercial speech doctrine. This is because citizens must have accurate information not only to knowledgeably participate at the ballot box but also to have meaningful freedom in economic life itself.