It deals with your scalp, rather than the dandruff already there, it simply prevents.
Head and Shoulders
The most common ingredient in anti-dandruff shampoo is Selenium Sulphide.
To get rid of dandruff, you can shampoo often with an anti-dandruff shampoo. Head & Shoulders is usually rated the best. If this does not rid you of dandruff, then it may be a medical issue.
Zinc
Tesco clear and confident anti-dandruff shampoo for sensitive scalps
To avoid dandruff, the sufferer must cleanse his scalp constantly with anti-dandruff shampoo.
Anything with tea tree oil.
anti dandruf and lice shampoo :3
Try using different anti dandruff shampoo.
It is bad, but not very serious. You should probably consider using an anti-dandruff shampoo or an exfoliating shampoo.
Nizoral Anti Dandruff Shampoo
If you're using an anti dandruff shampoo already but still have lots of issues with flakes, etc. you should probably see your doctor. You might have something other than dandruff as there are fungal infections of the scalp that can cause similar symptoms, or it could be a more severe form of dandruff or psoriasis that requires a prescription strength shampoo/treatment.