You may think this one is easy because you probably think you know the answer already. But you must realize that your type of hair may change, according to the season, what kind of medication your are taking, whether or not you have processed your hair (used chemicals on it), etc.. So the number one thing to remember is that you should re-evaluate your hair type often. Second, if you process your hair, it may not fall neatly into one category. Categories can include normal, oily or dry, fine or thick, color treated, permed hair, just to name a few. Different companies categorize their products differently. If your hair does not fall neatly into a category, (for example, you color-treat your hair, but products formulated for this leave your naturally, oily hair limp), this can be tricky when purchasing hair care products. If you process your hair, you should try out both a shampoo and conditioner formulated for your type of process first (i.e. color treated or permed). But if these products do not make your hair look its best, you may have to compromise.
For example: Let’s say that you have color treated hair and due to this, your ends are dry, but you also have an oily scalp. Shampoos designed for color treated hair just don’t seem to clean your hair enough to cut through the grime, so what do you do? Try using a shampoo for oily hair and a conditioner for color treated hair. Why will this work? All types of hair should concentrate shampoo at the scalp, and conditioner at the ends. This is because the hair at the scalp is newer, and therefore not as severely damaged as the hair at the ends. It is in a more natural state.
Therefore the shampoo will work on decreasing the oil at the scalp, while the conditioner works to moisturize the body of the hair (most processes result in dried ends). The moral of the story is that you do not have to use a shampoo and conditioner formulated for the same hair type. If your hair falls into two categories, and the same formulation for both shampoo and conditioner is not working, then use a shampoo formulated for the more natural condition (oily. fine, or dry hair) and a conditioner formulate for the processed condition (color treated or permed). Because shampoos for color treated hair often contain UV filters and ingredients to prolong the life of your color, you may want to only use the non-color treated shampoo when your hair is feeling especially greasy, or you may want to rotate shampoos. While it is essential to choose a product based on what hair type it is designed for, it is also necessary to scan the list of ingredients to purchase products based on their quality.