Robert F. Kennedy Jr. is going viral on social media after he was caught on camera adding a mysterious blue liquid to his in-flight beverage, and internet sleuths believe they know what it is. The leading theory among X users is that the prospective health secretary was dosing his drink with methylene blue.

Kennedy Jr. was spotted on a plane adding a blue liquid to his drink in a viral video that has sparked speculation online. Newsweek reached out to a representative for RFK Jr. outside of regular working hours via email for comment.

Conspiracy theorist Robert F. Kennedy Jr. is going viral again - this time for squirting blue liquid into a glass while flying on a plane. The clip circulating on online shows the 72-year-old anti-vaxxer - who is about to run the U.