Shampoos and Conditioners

Shampoos are designed to remove dirt, excess oil and dead skin cells from the scalp and hair.

• Unless your hair and scalp are unusually dirty or have lots of build-up, it's only necessary to lather once.
• Concentrate on the scalp, and don't scrub, as hair is at its most fragile when its wet.
• Most important, be sure to rinse well, or your hair may look flat and dull.

There are various cleansers, called 'surfactants', used in shampoo. Among the most common are Sodium or Ammonium Laureth Sulfate, Sodium or Ammonium Lauryl Sulfate, and TEA-Lauryl Sulfate. Of these, Sodium Lauryl Sulfate and TEA-Lauryl Sulfate tend to be somewhat harsh and can irritate sensitive scalps. Most shampoos (except the clarifying ones) also contain some conditioning agents like humectants, silicone and protein, but in much lower amounts than in conditioner. These stay on your hair until the next time you wash it. Other ingredients produce lather, help make the product thick and give it a nice scent and appearance.

Conditioners are made to protect hair from heat and styling damage, reduce friction both between individual hairs and between hair and your comb, moisturize, reduce static and impart shine. Generally, the longer you leave a conditioner on, the more chance it has to attach itself to the cuticle. Deep conditioning with heat is the most effective. But again, rinsing well is important unless you're using a light leave-in conditioner.

There's a long list of ingredients that are used in conditioners.

• Humectants like Glycerin, Panthenol and Quaternium-22 help bind water to the hair.
• Silicones (ingredients ending in the word 'methicone') add shine and moisturize the hair.
• Proteins fill in chips in the cuticle, making hair feel more full.
• And emollients, such as fatty acids and fatty alcohols (like cetyl alcohol, stearyl alcohol and stearic acid), oils and lanolin coat the hair to protect it and seal in water, although the latter two can be too greasy for many people with fine, thin hair.