With the harsh season change our hair tends to take a major hit. We start to notice more breakage and dryness. It is important to change your shampoo/conditioner depending on how your hair looks and feels, because every shampoo/conditioner has different pH level.
The pH levels in shampoos depend on their ingredients. Good-quality shampoos have pH levels between pH 5 and pH 7. Your hair contains a natural oil called sebum. The pH level of this is pH 5. Anything significantly higher or lower than this will strip your hair of its natural oils. In shampoos, anything above pH 7 is alkaline and anything below is acidic.
Acceptable pH Level Variations
Shampoos fall in the middle of the pH scale since they are between pH 5 and pH 7. Conditioning shampoos have formulations that lower their pH levels a bit. This provides better care for your hair. Cleansing shampoos have a higher pH level because their ingredients are for cleaning stubborn residue on hair. Therefore, you may find shampoos with levels from pH 4 to pH 9.
Effect of High pH Levels
Shampoos that have high pH levels are alkaline, and this can remove natural oils that are present in the scalp. It can also result in the loosening of the substance that holds hair shafts together. While effects of such shampoos look promising with the first few uses, their effects will eventually make your hair dry and brittle.
Effects of Alkaline and Acidic Shampoos
The pH levels in clarifying shampoos are usually more alkaline to allow the hair shaft to open up for a thorough cleaning. You can use alkaline-based shampoos to soften your hair. Alkaline-based shampoos are also used in hair straightening.
Conditioners and moisturizing shampoos are acidic to allow the hair shaft to soften and better retain moisture.
The pH Levels for Dry Hair
Dry hair is the most difficult to look after. For dry hair, choose shampoos that have a low pH level. This means their level of acidity is higher. These types of shampoos allow your hair cuticles to open up and take in moisture. They also help your hair to retain moisture.
Pointers on pH Levels
Find a shampoo that lists its pH level. Whenever you see the words moisturizing or hydrating, understand that the pH levels are low. Shampoos can also undergo the litmus test. You can easily find scales to measure against online. Just dip a litmus paper in your shampoo and compare its color to the available chart.
Source: pH Levels in Shampoos | eHow.com