Robert F Kennedy Jr has left social media users scratching their heads after the Health and Human Services secretary nominee was recorded administering droplets of a mysterious blue liquid into his drink on board a flight.

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.