How Long Does Semi Permanent Hair Dye Last? We Reveal How Often You Should Be Colouring Your Hair

How long does semi-permanent hair dye last? We decipher all your colour queries.  

Depending on the type of dye used, and your hair’s condition and colour, a semi-permanent hair dye can last anywhere from 6-8 weeks, or on average 28 washes.

Whether you’re decorating your Pinterest board with acid brights, burnt orange balayage, or bold berry hues, experimenting with colourful hair has never been so du jour. But before you think about jumping on the bold hair bandwagon, it’s important to know how often you should colour your hair and how the process can affect your strands.

Revealing the answers to your most pressing colour queries, ATH decodes how to choose which colouring technique is right for you.

Plus, our expert breaks down the chemical processes of different dyeing methods (from temporary hair colours to bleaching) and reveals how to make sure your hair stays in its best shape, whatever colour you’re coveting.

How Long Does Semi-Permanent Hair Dye Last?

How long does semi permanent hair dye last woman with blue hair
How often should you colour your hair and why? Credit:

If you’re not looking to make a permanent hair change, a semi-permanent hair dye could be the answer, usually lasting up to 28 washes.

Used to tint the hair with a colourful or slightly darker shade, temporary hair colour allows you to experiment with colour without making a lasting change.

It’s the perfect choice if you’re thinking about trying a new hue but aren’t ready to commit to a complete mane makeover, or you just want to add a hint of pigment to your locks for a festival.

How Long Does Permanent Hair Dye Last?

How long does semi permanent hair dye last woman with colourful hair
How long does permanent hair dye last? We break it down… Credit:

If you’re ready to commit 100% to new hair colour, opt for a permanent hair dye. This is a great way to get a lasting, rich colour, especially if you’re trying to touch up roots or cover pesky greys.

Permanent hair dye – especially bleach – is made to last and generally will have to be grown out of your hair as your roots come through, rather than it washing out.

A semi-permanent temporary hair colour, on the other hand, will gradually fade with each wash. So, if you’re looking to make a colour change that will last, permanent hair dye is your answer.

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How Long Does Bleach Last?

How long does semi permanent hair dye last woman with short blonde hair
How to repair and maintain bleached tresses. Credit:

Bleaching hair involves using chemicals to strip the hair of its melanin, so it appears lighter in colour. Bleaching is a permanent hair dye solution and cannot be washed out.

The hair needs to grow out any bleached sections but, if you want to backtrack on lighter locks, you can use a permanent or semi-permanent hair dye over the bleach. So, if needed, how soon can you re-dye your hair? As and when your hair stylist recommends would be the best course of action.

The same is true for highlights, balayage and ombre. All of these processes involve lightening the hair, sometimes with bleach or high-lift tint depending on your base hair colour and desired outcome.

In all cases, lightening the hair is a lasting change. So, if you’re not sure you’re ready to take the plunge, speak to your hairstylist about the alternative options available to you.

Whatever lightening technique you choose, it’s important to think about the permanent hair damage implications that come with bleaching. According to Peter Bailey, Global Technical Manager, Hair Care, “the chemical process inside your hair fibre breaks a number of the structural protein bonds leaving your hair brittle and more prone to damage.”

If you’ve taken the plunge and your strands are looking a little worse-for-wear, learn how to ‘repair’ bleached hair and rejuvenate damaged blonde locks.

How Often Can You Dye Your Hair? An Expert Weighs In.

How long does semi permanent hair dye last woman with blue afro
Follow our advice to keep coloured hair in tip-top shape. Credit:

While it can be tempting to swap from one hair colour to another on a whim, dyeing your hair can have a serious effect on how healthy or damaged it looks. We recommend waiting at least 6-8 weeks between dyeing to keep your hair in its best shape.

“Whenever you bleach, dye or chemically straighten your hair, you are causing significant damage to the fibre structure,” warns Peter. “All of these chemical treatments involve breaking a large number of the di-sulphide bonds which are the chemical bonds that hold the protein strands together.”

This effectively breaks down the hair fibre, leaving holes in the cortex and cuticle, making it more porous. As a general rule, the more porous hair is, the more dry, coarse and damaged it can appear. So if you want to maintain healthy-looking tresses, try colouring them less frequently.

“The more you colour your hair, the more protein you are losing from each individual fibre, making your strands difficult to comb, style and maintain, with an increased likelihood of split ends and breakage.”

If you’re looking for a chemical-free alternative, natural dyes like henna can give you a strong colour (depending on your original shade), without disrupting the hair fibre.

To help visibly repair the hair, scroll down for our curated product recommendations and hair repair techniques.

How Long Do Hair Dyes Last?

How long does semi permanent hair dye last asian girl with pink hair
Pink hair, don’t care. Credit:

Different types of hair dye can last anywhere between a single day to permanently changing your hair colour. There are two main factors that will influence how long your hair dye lasts. Firstly, what type (and strength) of colouring treatment you use and secondly: how you maintain your tresses.

So, how often can you colour your hair? With a wash in, wash out technique, the damage to the hair is lessened and allows you more dyeing options without the permanent damage consequences.

Colouring Sprays

Perfect for Halloween, colour sprays that come from a can coat the hair in a layer of pigment but don’t offer a long-lasting solution. They usually come out with one wash but – if you have very fair or porous tresses – be warned as they can stain the hair.

Hair Chalk

Can you dye your hair twice in one day? Yes, if it’s with hair chalk.

Perfect for festivals or themed parties, hair chalks allow your hair to become a canvas for colour – without the permanent consequences. Most will fade as the day wears on as they only cling to the surface of the hair but it’s always important to read the instructions before applying so you don’t end up with any stains or surprises…


Bleach is 100% permanent. You can dye your hair over bleached locks, but any strands that are bleached will have to grow out and cannot be removed any other way. So think twice before you decide to lighten up.

Permanent and Semi-Permanent Dyes

How porous (read: damaged) your hair is will have an effect on how vibrant your permanent or semi-permanent dye will look and last. As a general rule, permanent colours may fade but will have to be grown-out or dyed over if you want to change them, whereas a semi-permanent shade is made to be washed out.

How Do I Maintain Dyed Hair?

How long does semi permanent hair dye last woman with ginger hair
How long does semi-permanent hair dye last? Credit:

There are a few golden rules when it comes to looking after freshly-coloured locks:

1. Pick a Colour-Care Shampoo and Conditioner 

When looking after the condition and vibrancy of your dyed tresses, it’s important to add wash and care products that are designed for the job, like the Dove Colour Care Shampoo.

To decide which products deserve a spot in your shower, head to our ‘best shampoo for coloured hair‘ cheat sheet and pick the duo that are right for you.

2. Always Use a Heat Protectant

As the process of colouring is generally a chemical one, it’s important to treat dyed tresses with a lot of care. The first step? Applying a heat protectant to damp tresses before you even think about picking up a hair dryer.

The TONI&GUY Heat Protection Mist not only helps guard your strands against damage, it also helps detangle them – a huge bonus if your hair is feeling a little frizzy or fried. If you’re still puzzled, check out our guide to the best heat protectants for every hair type. You’re hair will thank you, trust us.

3. Hair Masks Are Your BFF

According to Peter, “chemically treated hair is way more fragile than non-chemically treated hair. Whenever the hair is washed, detangled and styled, the chemically treated hair is more likely to lose more cuticle cells from the outside of the fibre.” This leads to increased chances of breakage and split ends.

To help combat this, use a range that is designed to help counter the appearance and feel of coarse strands.

Formulated to help visibly repair 7 types of damage, add the TRESemmé Biotin+ Repair 7 Intensive Recovery Mask to your grooming routine 1-2 times per week. Following the TRESemmé Biotin+ Repair 7 Shampoo, it will protect, strengthen and nourish your hair to leave it healthier-looking.

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