Research on the effects of social media has evidenced their influence on public opinion concerning health issues. However, there are scarce analyses that pay attention to this influence when health advice generalizes certain groups' sexual practices. This generalization occurred with monkeypox, men who have sex with men, after two World Health Organization's (WHO) recommendations launched in 2022. Therefore, this is the issue that will be deeply explored in the article. Drawing on the methodological strategy of social media analytics (SMA), 2313 tweets have been reviewed focused on people's reactions in front of WHO's statements of July 2022 about monkeypox and men who have sex with men behaviours. Findings illustrate that there is positioning against the generalizations caused due to WHO's statement creating a public discourse against the stigma of homosexual and bisexual men. This positioning is directly linked with people's claims to follow the evidence and valid claims on public health issues. Using social networks for claiming the use of rigorous data and evidence may contribute to a significant change in public opinion and health organizations.