I began using apple cider vinegar to help diminish the dark spots caused by melasma. I was not pleased with the results that I received. The current spots that I did have seemed to become darker then they have ever been, and a rapid increase of spots, some of which appeared on areas of my face that have never had them such as my chin. I continued using it for approx. 3 weeks then decided it was only making the problem worse. Since I discontinued using apple cider vinegar the spots have not increased and have begun to lighten. Currently I started taking msm 1000mg once a day, it is day 4 so I am patiently awaiting.