Prankster 'puts Viagra in flatmate's protein shake'

A funny video has emerged of a man pranking his flatmate by putting Viagra in his protein shake.

The footage, shot on Sunday in Ramsgate, UK, shows the man carefully emptying viagra pills in his friend's protein shake and gluing the lid back before he heads to the gym.

Moments later, the gym goer can be seen coming back with his hoodie tied around his waist to cover the pills' effect.

Remember, it's important not to try this at home as this was a prank filmed for entertainment purposes and it can be dangerous.