Semi-permanent hair dye is a popular option for those looking to cover greys or change up their hair color without the harsh chemicals and long-term commitment of permanent dye. But how long does it actually last on grey hair? Let’s take a closer look.
What is Semi-Permanent Hair Dye?
Semi-permanent hair dye contains no ammonia or peroxide, which means it doesn’t penetrate the hair shaft or permanently alter the natural pigment. This makes it less damaging than permanent dye. Semi-perm dye works by depositing temporary color onto the hair’s outer layer, or cuticle.
The color molecules are too large to fit into the cortex, where permanent hair pigments reside. This means the color washes out over time and fades gradually with each shampoo. Semi-permanent dye is therefore less permanent than demi-permanent dye, which does contain a low level of peroxide to open the cuticle slightly and last longer.
How Long Does Semi-Permanent Hair Dye Last on Grey Hair?
On average, semi-permanent hair dye tends to last 4-8 shampoos, or around 4-6 weeks on grey hair. However, there are several factors that affect its longevity:
1. Type of Grey Hair
Natural grey hair with over 50% grey coverage will hold semi-permanent color the shortest – around 4 weeks. Grey regrowth with less than 50% coverage tends to hold color a little longer at 5-6 weeks.
2. Porosity of Hair
Hair porosity refers to your hair’s ability to absorb and retain moisture and color. Those with high porosity hair tend to find semi-permanent color washes out faster. Low porosity hair is better able to trap dye inside the cuticle for longer lasting results.
3. Condition of Hair
Dry, damaged hair tends to grab onto color more which can initially make it appear brighter. But it also washes out faster than on healthy, conditioned hair which can better retain semi-permanent dye. Proper conditioning is key for longer lasting color.
4. Frequency of Washing
Frequent shampooing, especially with clarifying or sulfate-containing shampoos, will cause semi-permanent color to fade faster. Washing hair less often helps extend the life of the color.
5. Use of Hot Water
Rinsing hair in hot water opens up the cuticle, causing semi-permanent color molecules to escape. Lukewarm to cool water allows cuticles to stay closed longer to preserve color.
6. Exposure to Sun
UV rays cause semi-permanent hair dye to fade more quickly. Hair that is frequently exposed to sunlight won’t hold the color as long.
7. Swimming
Chlorine and saltwater can strip semi-permanent dye from grey hair more rapidly. Always wet hair first and apply conditioner before swimming to help protect the color.
8. Use of Styling Tools
Frequent use of hot styling tools like blowdryers, straighteners and curling irons causes semi-permanent dye to fade faster by opening the cuticle.
Here is a table summarizing how long semi-permanent dye typically lasts based on percentage of grey hair:
| Grey Hair % | Duration of Color |
|---|---|
| Less than 25% grey | 6-8 weeks |
| 25-50% grey | 5-7 weeks |
| 50-75% grey | 4-6 weeks |
| 75-100% grey | 3-5 weeks |
Maximizing Longevity of Semi-Permanent Color on Grey Hair
While semi-permanent dye does wash out over time, there are tips to help extend the life of your color:
- Shampoo less frequently, aiming for every 3-4 days
- Use a sulfate-free, color-safe shampoo and conditioner
- Rinse hair in cooler water and avoid very hot water
- Limit use of hot styling tools like blowdryers, flat irons and curling wands
- Apply a UV protecting product before sun exposure
- Wear a swim cap and use pre-swim conditioner when swimming
- Use a color-depositing conditioner or gloss between dye touch-ups
- Get a trim every 6-8 weeks to remove faded ends
How to Make Semi-Permanent Dye Last Longer
You can help semi-permanent color deposit better and last longer on grey hair in the following ways:
- Shampoo hair the day before: Natural oils can prevent dye from adhering. Shampooing the day before stripping oils allows better saturation.
- Use a clarifying shampoo: Product buildup can prevent proper absorption. A clarifying wash helps remove residue.
- Dry shampoo morning of: Adding dry shampoo absorbs excess oils for optimal color deposit.
- Section hair: Sectioning hair allows even saturation needed for good coverage.
- Apply to damp hair: Color adheres better to damp hair than dry hair.
- Comb through: Combing product through coats every strand.
- Don’t rinse right away: Leave on for 15-30 mins before rinsing for deeper penetration.
- Rinse with cool water: Hot water opens the cuticle causing color to wash away faster.
- Use a sulfate-free shampoo: Sulfate-free cleansers help lock in color.
- Use dry shampoo between washes: Extend time between shampoos to make color last longer.
How Often to Reapply Semi-Permanent Hair Dye
To maintain vibrant color and grey coverage, plan to reapply semi-permanent dye every 4-6 weeks. Keep an eye on when you start noticing regrowth and fading. Reapply as soon as you see your roots coming in or color looking dull. The more promptly you reapply, the better the coverage.
Many find they need to dye roots more frequently than lengths. This may mean just doing a quick root touch-up in between full head applications. Some also alternate semi-permanent dye with temporary root concealer sprays to stretch out applications.
Semi vs Demi-Permanent Dye for Grey Hair
While semi-permanent dye washes out in 4-6 weeks, demi-permanent color with a low level of peroxide can last 6-8 weeks on grey hair. This lighter developer helps open the cuticle just enough for the dye to penetrate slightly deeper.
Demi-permanent is better able to cover stubborn greys and produces more natural-looking results. However, demi-permanent hair dye contains some peroxide so it will cause minimal damage. It’s gentler than permanent dye though and can be a good option for grey coverage with longer lasting results.
How to Remove Semi-Permanent Hair Dye
Semi-permanent dye will gradually wash out over 4-6 weeks. But if you want to speed up removal or drastically lighten, here are some options:
- Use clarifying shampoo to help strip color more quickly
- Make a baking soda paste to remove stained hair color
- Use an at-home color remover product according to instructions
- Try vitamin C powder mixed with shampoo to fade dye
- Get a professional color removal service for fastest results
These removal methods can dry out hair so be sure to use a deep conditioner after. It’s safest to let a professional remove semi-permanent color but at-home options can work well too.
Conclusion
Semi-permanent hair dye provides an easy, low-commitment way to cover greys and try new colors. While it won’t permanently color grey hair, it can last a respectable 4-6 weeks when cared for properly. Work with your natural hair color and texture for the best results. With a few tweaks to your haircare routine, you can maximize the longevity of color and enjoy weeks of vibrant, shiny locks.
