Quick answer: semi-permanent hair dye coats the hair with colour without a developer, so it doesn't lighten your hair and fades gradually with every wash, usually over a few weeks. How long it lasts depends on your hair (lightened, porous hair grabs colour but releases it faster), the shade (bright reds and blues fade at different speeds) and how often you wash. Demi-permanent colour uses a low-strength developer and lasts longer; permanent colour can lighten and grows out rather than washing out.
How does semi-permanent hair dye work?
Semi-permanent dyes are "direct" colours: ready-to-use pigments that you apply straight from the tube, with no mixing and no developer. The pigment sits on and just inside the outer layer of the hair, which is why it fades a little with every wash, and why it can't make hair lighter than it already is.
Semi vs demi-permanent vs permanent hair colour
- Semi-permanent: no developer. Deposits colour only, can't lighten, fades gradually with washing, and leaves no hard regrowth line. Great for bright fashion shades and refreshing tone.
- Demi-permanent: mixed with a low-strength developer, so colour penetrates a little further and lasts longer. Still can't lighten. Often used for glossing, toning and blending grey.
- Permanent: mixed with a developer that opens the hair so colour can lighten and change it from the inside. It doesn't wash out; it grows out, leaving regrowth.
How long does semi-permanent hair dye last?
Usually a few weeks, but there's no single number, because it depends on:
- Your hair's porosity: lightened or bleached hair takes bright shades vividly but also lets them go faster. See hair porosity explained.
- Your starting colour: bright shades show best on pre-lightened hair. On dark hair they may only show as a tint in the light.
- The shade: some pigments hold on longer than others.
- How often you wash, and how hot the water is.
Our semi-permanent colour: Enhancing Color Pigments
Enhancing Color Pigments are ready-to-use direct colours with no activator needed. They leave hair soft and shiny, enhance and revive colour, and fade gradually with no regrowth effect. Use them for a whole new look, to revive faded tones, to add contrast to existing colour or for bold fashion shades. There are six shades: Bright Red, Fierce Copper, Rich Silver, Neon Pink, Blue Velvet and Tropical Green. Always follow the instructions in the pack.
Thinking of going red or copper? Read semi-permanent red hair dye to see how Bright Red and Fierce Copper show on different starting colours.
Shade guides: pink hair dye, blue hair dye, silver hair dye and red and copper.
How to make semi-permanent colour last longer
- Wait before the first wash as long as you can, ideally a couple of days.
- Wash less often, and use dry shampoo in between. See how to use dry shampoo.
- Rinse with cool water. Hot water opens the cuticle and releases colour.
- Use a gentle, colour-care shampoo, such as Protective Shampoo, or a sulphate-free shampoo.
- Protect from heat and sun, both of which fade colour. Read how to make hair colour last.
Frequently asked questions
Does semi-permanent dye damage hair?
Semi-permanent colour has no developer and doesn't lighten, so it's much gentler than permanent colour. Bleaching first to make bright shades show is what causes damage.
Can semi-permanent dye cover grey?
It can tint or blend grey, but won't cover it fully. For full grey coverage, permanent colour is usually needed: ask your colourist.
Will semi-permanent dye show on dark hair?
Only subtly. For bright fashion shades, hair usually needs to be lightened first.
How do I remove semi-permanent dye?
It fades with washing. A clarifying wash speeds things up. For a fast change, ask your salon.
How do I get hair dye off my skin?
See how to get hair dye off your skin.
About the author
Charlotte Read has spent six years in the hair industry with Insight Professional and holds a First Class BSc in Business Management and Marketing. She writes with reference to real salons across social media and the wider Insight community, and draws on the Insight office team, who between them bring over 100 years of combined experience on salon floors.
Where technical expertise is needed, Charlotte consults Lorraine Matic, Head of Insight UK Education, who brings over 38 years of global experience in colour, technique and hair science.