Pigment cells in your hair follicles produce melanin, the chemical that gives your hair its colour. These cells begin to die as you become older. New hair strands grow lighter in colour and take on various colours of grey, silver, and white as a result of the lack of pigment. The genes you receive from your parents play a big role in when and how much your hair greys. Neurofibromatosis, tuberous sclerosis, vitiligo, alopecia areata, vitamin B12 deficiency, and thyroid issues, for example, can cause hair to become grey. Uncontrolled stress levels have been linked to hair greying in recent studies.

When ammonia dyes are used frequently, the cuticle becomes damaged, enabling moisture to escape. Frizzy, dry, and brittle hair are the results of this. When ammonia is used on the hair, it has the potential to enter the bloodstream via the scalp. Ammonia is also a bleaching agent which can make you lose hair in the telogen phase.

On the other hand, ammonia-free hair colours are gentle, look natural and equally effective in giving you long lasting coloured hair.

PPD (paraphenylenediamine) is a chemical compound that is commonly used in permanent hair dyes. Rashes, contact dermatitis, itching, blisters, scars, and possibly dangerous systemic consequences are all allergic reactions to PPD.

Hair dyes containing PPD have been linked to cancer and mutagenicity. Aside from that, PPD has the potential to cause acute and subacute toxicity, such as allergic contact dermatitis.

However, hair loss in the scalp caused by PPD-containing hair colours is uncommon.

Yes, colouring your hair frequently with the commercially available permanent and semi-permanent hair colour causes substantial damage to your hair. To understand this, you first know what a hair colour does to your hair. Hair is made up of two parts: the root and the shaft. When you colour your hair, you colour the shaft rather than the root. The cuticle, cortex, and medulla are the three layers that make up the shaft. The medulla has a hollow core, the cuticle is made up of densely packed cells, and the cortex is made up of natural colour pigments (these are the pigments which determine the colour of the hair). When you employ colouring chemicals, they either remove the original colour from the hair shaft, replace it with a new colour, or do both.

In short, when you colour your hair, the hair's protein structure gets altered.This means that the hair loses its strength, its ability to manage the heat from styling products, and even reduction in the thickness of your hair.

This is why you should always consider colouring your hair at the prescribed time intervals.