Pinterest uses AI classifiers and URL-level blocking to prevent the spread of health misinformation — including content questioning vaccine safety — and became the first major social media platform to ban climate change misinformation outright in April 2022. Searches for vaccination-related topics are restricted to results from authoritative health sources like the WHO, CDC, and the American Academy of Pediatrics only. These policies have been in place in various forms since 2017.

The enforcement system combines machine learning classifiers with a curated blocklist of URLs and domains known to host health or climate misinformation. For vaccine-related searches, Pinterest suppresses all non-authoritative results algorithmically, rather than simply removing individual Pins. The climate misinformation ban, introduced in April 2022, prohibits ads and organic content that deny the scientific consensus on climate change. Pinterest partners with external expert organizations to identify emerging misinformation trends. There has been documented internal tension: a 2020 STAT News investigation found that the company's misinformation policies were developed by a small group of employees who faced resistance from colleagues and leadership.