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.

RFK Jr, a known vaccine skeptic and conspiracy theorist, was filmed administering several pipette-fuls of the Cobolt blue-colored liquid into his glass. The video emerged on Wednesday as the 72-year-old awaits Senate confirmation to be the nation’s top health official.

Robert F. Kennedy Jr. cleared a crucial hurdle for confirmation as Health and Human Services secretary. Here's what happens next in the Senate

The Senate Finance Committee on Tuesday voted along party lines to support the nomination of Robert F. Kennedy Jr. as Health and Human Services secretary—a key victory for one of President Donald Trump’s most controversial cabinet picks, after some GOP lawmakers remained on the fence due to Kennedy’s claims about vaccines.

Robert F. Kennedy Jr. has cleared his first hurdle to become the nation’s top health official as the Senate finance committee voted to advance his nomination for a floor vote.