– The appearance of gray hair can happen at almost any time in a person’s life, and it is not always greeted with great enthusiasm by men or women. Some individuals have a family history of the pre-mature onset of gray hair, which can allow it to appear as early as their 20s, while other people retain their natural color well into later years before gray hairs begin to show. Whenever gray hairs start to appear, at whatever age, many people want to at least delay the look of gray hair for a while. Fortunately, there are many products available to let them easily cover the gray. read more about cover gray » | resource library for hair care »
The physiology of gray hair is still not yet completely understood, and there are many theories about the exact mechanism that causes it. In practical terms, gray hair simply means that the melanin, the pigment that gives hair its color and which is normally deposited in the cortex (the second layer) of hair, is no longer produced by the melanocytes at the base of the hair follicles. Associated with gray hair are other changes in hair structure: The overlapping plates on the cuticle, or outer protective layer of the hair strand, begin to become roughened. This means that the hair strands appear to be thicker, lose their moisture level and, as a result of dehydration, become more brittle and prone to breakage. Gray hair is more difficult to dye and has a tendency to lose new hair coloring that is added.
If someone decides to cover their gray hair, there are several options. When less than 50% of the hair strands have turned gray and is still at the "salt and pepper" stage, some people color the gray as highlights. Products that take this approach are usually semi-permanent coloring, which typically lasts through six to 10 shampoos. Other products are formulated to cover the gray with an ingredient which reacts and darkens when exposed to the air, which allows the hair to gradually "return" from gray and even enables the user to choose how much gray to leave showing.
Another approach is to color the hair entirely. Unlike other hair coloring processes, however, the products specifically made for covering gray hair are specially formulated. Because gray hair strands are already stressed by compromised cuticle layers and being prone to dehydration, coloring for gray hair tend not to include ammonia. Under other circumstances, ammonia is usually provided to help open the cuticle layer, to allow the bleaching and coloring ingredients to go to work on the cortex layer of the hair strands; this process could damage already weakened gray hair.
Those products which are specifically designed for coloring gray hair are also formulated to condition, hydrate and protect the hair strands. This helps to prevent the pigments in hair coloring from quickly leaching out of the hair, which would make the hair fade and quickly return to gray. These conditioning formulas also often include ingredients to protect the hair from the ultraviolet waves from the sun, which can rapidly fade hair coloring.