prescription ones and non-prescription ones, including Vc. please read:
http://bbs.wenxuecity.com/health/383710.html
you can try this:
銀耳富有天然植物性膠質,加上它的滋陰作用,長期服用可以潤膚,並有祛除臉部黃褐斑、雀斑的功效;
http://bbs.wenxuecity.com/health/397856.html
do you use 避孕藥或避孕環嗎?if yes, stop it. they may cause this problem - disturb your hormone.