I have been hearing a LOT recently about how sulfate free shampoos and conditioners are better for you. If you look at your list of ingredients in MOST shampoos you will see this ingredient listed:
Sodium Lauryl Sulfate.
This is the main thing that causes your shampoo to foam up and create those wonderful suds that we all assume are vital to clean your hair.
The thing is that Sodium Lauryl Sulfate (SLS) is actually a harsh salt and it strips your hair. This is probably the reason why you notice your hair is so rough after using shampoo alone and you therefore need to use conditioner.
The newest talk is that you do not need to use SLS on your hair to get it clean and you can use Sulfate Free shampoos and conditioners instead. These have an ingredient called Sodium Lauryl Sulfoacetate instead, which is supposed to be better for your hair and skin as it is milder.
You can read up all about the chemical breakdown of the two different ingredients elsewhere but in short Sodium Lauryl Sulfoacetate is much gentler on your hair and skin.
I started using L'Oreal Sulfate Free shampoo and I hope that it is truly better for my hair. I did notice after one use that my hair did not feel as rough as with other shampoos, but one use is not enough to make a really good decision.