I have used the SkinMedica Neck cream for over a year, every night! I had a horrible reaction a few days ago! I know that is what caused it because that is the only thing that I put on my neck! It's like a burning blister sunburn! The thing that really puzzles me is that I've used it for so long without a reaction. I had a reaction to another SkinMedica product but it was after using one time. I know one thing, I will NEVER use their products again!