Permanent vs Semi-Permanent: Our Tips for Choosing The Right Hair Dye

By Maria Rogerson

May 30, 2024Hair care

Hair dyeing has been long celebrated as a powerful form of self-expression. It allows you to experiment with different colours and styles to reflect your unique personality and identity. Some love experimenting with bold and vibrant hair colours, while others prefer more natural or subtle tones. 

If you have ever searched for daying options, you must have noticed that there are permanent and semi-permanent box dyes. To make sure you choose a pigmented hair dye that delivers even results, understanding the differences between permanent and semi-permanent options can serve as a stepping stone in the search for the best dye option for your hair.  

Permanent vs Semi-Permanent: Understanding the Differences 

Hair Dye

When it comes to colouring your hair, the type of dye can impact both the look and health of your locks. Here are some major differences between permanent and semi-permanent dyes that can help you choose the right hair day and achieve the best results.  

Chemical Composition

Those who have never coloured their hair before are mostly concerned with the question “Is dye safe for hair? There is no black-or-white answer to this question. Although some experts warn about the safety of hair days, this will largely depend on the chemical composition of the dye. 

One of the most common ingredients found in hair dyes is ammonia. Although some consider it to be damaging to the hair, others believe that this statement is exaggerated. However, many formulas don’t have ammonia in their composition, regardless if they are permanent or semi-permanent. 

When it comes to the rest of the ingredients, permanent colours typically contain hydrogen peroxide which penetrates the hair shaft and alters the colour permanently (until you let your natural hair colour grow out). The chemicals in permanent dyes open the hair cuticle to allow the colour molecules to enter and do their job. The result is a long-lasting colour that won’t be completely washed out after a few hair washes. 

A semi-permanent hair dye colour means that the colour is designed to last for only a certain time, after which, the colour will gradually fade. These dyes work by coating the hair shaft with hair colour, without the colour molecules entering the shaft. As such, they’re more gentle on the hair, and many prefer them because they wash out after a short period. 

However, many brands are focusing on producing gentle formulas for permanent hair dyes that not only colour the hair but also contain nurturing oils and other healthy ingredients to help maintain the health of the hair shafts. 

Colour Result

Permanent hair colours provide more intense and long-lasting colour results. Since they typically provide stronger colour results than semi-permanent dyes, you can use them to lighten up or darken your hair by several shades. They are also more effective in covering grey hair and achieving dramatic colour changes. 

As for semi-permanent dyes, although they typically provide more subtle colour results, you can still find great box dyes that can work amazingly well. Many of them can also lighten up your hair colour to several shades and give you strong and vibrant results. However, when compared to permanent options, the colour vibrancy is not as strong. 


Permanent dyes typically can provide more coverage to grey or white hair. This is due to their ability to penetrate deep in the shaft which ensures uniform colour distribution. 

On the other hand, semi-permanent hair colours are somewhat less potent when it comes to grey coverage. This means that the percentage of grey coverage is less than that of the permanent ones, especially when it comes to stubborn grey hairs. 


The biggest drawback of permanent hair colours is their potential to cause damage to the hair, especially if the hair is frequently coloured. Also, once applied, the hair colour cannot be easily removed or corrected without professional assistance. To ensure the hair dye you buy does not damage your fine hair, look for formulas with nurturing oils and ingredients that do not contain ammonia. 

Although semi-permanent colours are gentler on the hair, they typically have significantly short colour lasting and fade more quickly, especially with frequent shampooing. They do not provide permanent colour changes as permanent dyes do.

Major Considerations


Assess Your Hair Health

If your hair is prone to dryness and breakage or has already been damaged in the past, go for semi-permanent colours as they can help you achieve what you want, without further damaging your locks. 

If you have virgin hair or very thick, strong and healthy hair strands, you’ll be just fine with using permanent hair colour. Choose a formula with nurturing oils and develop a proper hair care routine to keep the shafts in optimal health.  

Desired Colour Intensity

If you prefer stronger and longer-lasting colour results, choose permanent hair dye. If you’d like to have a temporary change, which can allow you to experiment with a wider range of hair colours, go for semi-permanent ones. 

Maintenance Requirements 

When choosing between one or the other option, it’s important to assess your willingness and budget capacity for keeping up the hair colour. Permanent options require less frequent touch-ups, which means they’re ideal for those with busy lifestyles or tight budgets for frequent salon visits. However, they do require more intensive care and maintenance as well as regular deep conditioning. 

As for semi-permanent ones, they require frequent touch-ups since they fade gradually with each wash. But if you love changing hair colours often, then this could be the perfect option for you. Additionally, semi-permanent dyes are usually gentler on hair and require less maintenance overall. They can also be easily applied at home, saving you time and money.