I absolutely love these necklaces. I bought one previous from a different company but my sons necklace somehow got lost at school. He needed another one and found this one. The color is beautiful!!! These 100% work. I never used them on my other kids since I never knew about them but I wish I did. I never had issues with my little guy when he was teething. Now that I have a newborn I will for sure be getting another one for him as he will be teething soon!