I once heard....

If my hair is greasy, I should stop using Conditioner as it'll only make it worse.....

 

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If your hair is greasy it's usually because of an over prodction of sebum (a substance secreated from the tissues of you scalp)  

Continue to use your conditioner, just limit it to the lengths and ends of your hair. If you find after washing your hair it is still greasy it may be suitable to apply a little dry shampoo to the roots. This will absorb any excess moisture.