Plucking out your first grey hairs: a harmless action or a gesture with consequences?

The appearance of white hair is a phenomenon that affects everyone at some point in their life. Some people find it harder to accept than others, but it's important to remember that it's a natural process. From a biological perspective, it is explained by the gradual loss of activity and number of melanocytes in the hair bulb, cells that synthesise melanin. Without melanin, the hair fibres lose their pigment and turn white.

Furthermore, the amount of catalase, the enzyme capable of breaking down hydrogen peroxide, decreases over time. However, hydrogen peroxide is a by-product of the hair growth reaction and triggers a chain reaction leading to the degradation of melanin. These various mechanisms explain why one day we notice a white hair on our head.

It is sometimes suggested that if one plucks out a white hair, several will grow back in its place, but this is not the case. Indeed, hair pigmentation is determined by the proportions ofeumelanin, a dark pigment, and pheomelanin, a lighter pigment, within the hair fibres. These are two types of melanin synthesised by melanocytes.

Pulling out a white hair does not affect the ability of melanocytes to produce melanin in other follicles. Furthermore, hair grows according to an independent growth cycle for each follicle, with phases of growth (anagen phase), rest (catagen phase) and shedding (telogen phase). When a hair is plucked, the cycle of other hair follicles is not disrupted.

However, it is still advised against plucking out your first grey hairs. Besides being only a temporary solution to hair whitening, this action is harsh on the scalp and contradicts the hair renewal cycle. In defence and to fill the void left by the hair in the hair follicle, the scalp responds by stimulating the activity of the sebaceous glands, which are responsible for sebum production. As a result, hair may appear greasier. It is also possible that some people experience scalp itchiness after plucking a large number of hairs.

There are several options available to you if you wake up one morning to discover the appearance of your first grey hairs. The first and simplest is to ignore them. After all, if there are only a few, there's a good chance that no one will notice them, and even if they do, remember that it's a natural process.

If your white hair bothers you, you can also choose to conceal it, by changing your hairstyle, strategically placing your strands, or even resorting to hair dye or highlights. If you opt for the latter option, we advise you to consult a professional hairdresser, as colouring hair is quite technical and it's not easy to do it yourself.

• RAWNSLEY J. & al. Hair biology: Growth and pigmentation. Facial Plastic Surgery Clinics of North America (2018).