Grey hair at an early age can have various causes, such as vitiligo, vitamin B deficiency, thyroid imbalance, constant and extreme stress, alopecia areata, bad diet, etc. but its greatest trigger is genetics, causing the premature death of pigment-producing cells in hair follicles. When it comes to treating grey hair caused by other health conditions then the focus should be on tackling the primary reason. In treating genetically determined, premature grey hair, any effective therapy should involve interference with our genes. However, at the moment, no such treatment exists that can halt or reverse the dying of pigment-producing cells called melanocytes. There are some commercial products out there, though, containing vitamins, minerals and a Chinese herb Fo-Ti that are said to stop and reverse grey hair but the only evidence supporting the claims made by their marketers refers back to the old Chinese legend of an old villager, Mr He, from one thousand years ago. Vitamins B, namely PABA and folic acid, have been observed to stop greying in individuals with diets poor in vitamins B but they cannot help reverse grey hair in people suffering from chronic vitamin B deficiency, let alone in cases of genetically-determined grey hair.

Therefore, the only available grey hair treatment option for premature and age-related grey hair is to cover it. There are two principal colouring options for covering grey hair, which include hair dyes and progressive hair colorants. Hair dyes can be temporary, semi-permanent, demi-permanent or permanent, depending on the durability of their colouring effects. The ability of the pigment molecules to penetrate into the hair shaft determines the stability of the hair colour. Each hair consists of at least two layers, the cuticle, which is an outer protective layer, and the cortex, which is hidden under the cuticle. Permanent hair dye is, as its name says, the most stable of the hair colouring options, as its large molecules get trapped in the cortex of the hair and resist being washed out but it is also the most drastic method of dyeing hair. Hair dyes are popular, especially with female consumers. Men usually look for more subtle options of covering their grey hair as for a man dyeing hair is socially less acceptable. Progressive hair colorants, with their slow and gradual mode of action, seem to be the right product for men.

The marketing of progressive hair colorants is typically targeted at male customers but they can be also successfully used by women. These products colour hair gradually and unnoticeably and only affect your grey hair. They can be applied selectively so that you can leave certain areas untreated to look more natural. Progressive hair colorants are easy to apply, no plastic gloves are needed to apply them, and you just have to spread them on your white areas. Their mechanism of action consists of the chemical reaction involving one or two substances from the colorant, which in the presence of atmospheric oxygen produce synthetic pigment on the surface as well as in the pores and in the cortex of your hair. As the substance is drying in the air, the chemical reaction begins and lasts until the next shampoo wash. Hence, the longer the substance stays in your hair the better. The downside is that progressive hair colorants have to be reapplied relatively frequently, which makes them more expensive compared with the majority of traditional hair dyes. Progressive hair colorants are either metallic based or use organic chemicals.

The occasional controversy surrounding these products results from a wrong understanding of their mechanism of action and the purpose they were designed for. They were not meant to cover all your grey hair with a single application. For people with more than 50% of their hair white, it is almost impossible to achieve full white hair coverage with these products, no matter how often they apply them. They were designed for people who want to reduce the amount of their grey and wish to do it discretely and unnoticeably. Frequent shampooing reduces the effectiveness of these products as does exposure to direct sun.