It works by reacting with a girl’s body chemistry.
And each £12 tube comes with a colour chart so men can work out how randy their partner is feeling. The Mood Swing Emotionally Activated Lip Gloss was invented in California.
A spokesman for makers Too Faced said: “The colours change depending on your emotional state.”
Dating expert Lorraine Adams said: “This is the ultimate date ice-breaker.
“But using it every day could get embarrassing. Would you really want the man next to you on the bus to know if you’re turned on?