<p>Social media have become key sources of nutrition-related information, but the high prevalence of misinformation is increasingly concerning. We tested the effectiveness of source verification labels (signaling a content creator’s expertise) and message accuracy labels (communicating the [potential] incorrectness of the content) on message engagement intentions (liking/sharing the social media post) and persuasion (attitudes and behavioral intentions), mediated by perceived information credibility. An online experiment was conducted using a 2 (source verification label: present vs. absent) by 3 (message accuracy label: refutational fact-check vs. accuracy prompt vs. absent) between-subjects design. Participants (<i>N</i> = 275) viewed an Instagram profile and a nutrition-related video post with or without source verification and/or message accuracy label. Outcome variables were assessed after exposure. The presence (vs. absence) of message accuracy labels reduced message engagement intentions and message persuasion through information credibility, and these effects were stronger for refutational fact-checks (vs. accuracy prompts). Source verification labels did not affect any of the outcome variables, and neither did the interaction between the two label types. Findings suggest that by decreasing information credibility, message accuracy labels are a promising strategy to counter the spread and impact of nutrition-related misinformation, especially when they communicate the inaccuracy of specific claims.</p>