Abreva
"I got a cold sore yesterday morning, it was quite small and barely noticeable. I put abreva on and put it on like 10 times and when I woke up this morning it was bigger and more painful. It does not work. I don't get cold sores quite often, only when I'm very sick or physically drained (I'm a lifeguard and swim teacher). This was a huge disappointment, especially for how expensive it was."