Hair Lightening Spray
Hair Lightening Spray
Author: Jenna White | San Francisco Hairstylist
June 19th, 2021
June 19th, 2021
For decades, sun or heat activated lightening sprays (a.k.a. sun-in) have promised sun-kissed hair. These sprays have a soft brightening effect that ideally results in a natural looking highlight that you’d get from sun exposure. Many people opt for these sprays when going for a DIY approach, but are unfortunately unaware of the repercussions of unwanted outcomes, which can be worse than expected. Read on to learn more about how sun-in works and what to be aware of if you want to try it.
How do lightening sprays work?
The main ingredients in lightening sprays are water and hydrogen peroxide, which break down the melanin in your hair to produce a lightening effect. This is similar to what's used in bleach when stylists lighten your hair at the salon, with the key difference being how strong it is (sun-in has been watered down) and the quality of the conditioning ingredients used (professional grade products have higher quality conditioning agents). Other common sun-in ingredients include oils and fragrances that have no effect on the lightening process. Often the pH in these products can be more acidic than the 3% pH level of the hydrogen peroxide used on cuts and scrapes. You can check out this video by YouTuber Cosmo Dad to learn more.
How should I apply lightening spray when using it?
Make sure to check the product label for specific instructions. In general:
Will lightening spray work on hair that has been previously colored (lightened or darkened)?
This type of product will usually not work on hair that has been previously colored. On hair that has been darkened, it will likely not work at all. On hair that has been lightened, it may lighten the hair a bit more, but you risk damaging your strands by applying a lightener over pieces that have already been lightened (see this video by YouTuber Leda Fazal. Sun-in works best on hair that is between a chocolate brown and a caramel brown, or lighter, that has never been colored.
Will it lighten red hair?
Yes, it will lighten naturally red hair between a deep copper and a light auburn.
What will it do to gray hair?
Sun-in is a hair lightener, not a colorant, so it will not do much to gray hair. However, it may take any yellowish tints out during the lightening process.
Does it need sunlight to work?
These types of products are usually heat activated. The sun or a blowdryer will start the lightening process.
Will hair fade back to its natural color eventually after applying sun-in?
Only new hair that grows in will be your original color. Any pieces that have been colored with sun-in are permanently altered, and may even continue to lighten a bit over time.
What are some of the unexpected repercussions of using lightening sprays?
The obvious pros of sun-in sprays are that they're cost and time-effective. Some of the less-known potential cons include:
Check out the video below by YouTuber Leda Fazal to get more insights on the potential cons.
How do lightening sprays work?
The main ingredients in lightening sprays are water and hydrogen peroxide, which break down the melanin in your hair to produce a lightening effect. This is similar to what's used in bleach when stylists lighten your hair at the salon, with the key difference being how strong it is (sun-in has been watered down) and the quality of the conditioning ingredients used (professional grade products have higher quality conditioning agents). Other common sun-in ingredients include oils and fragrances that have no effect on the lightening process. Often the pH in these products can be more acidic than the 3% pH level of the hydrogen peroxide used on cuts and scrapes. You can check out this video by YouTuber Cosmo Dad to learn more.
How should I apply lightening spray when using it?
Make sure to check the product label for specific instructions. In general:
- For all-over lightening:
- Spray damp hair generously with the sun-in product
- Comb the product through your hair evenly
- Blow hair dry and then sit outside in the warm sun, or let it air dry while sitting in the sun (the sun isn't necessary to activate sun-in, the heat of a blowdryer alone will do the job)
- For a highlighted look:
- On damp hair, select thin sections, separate them out and spray each section generously
- Blow hair dry and then sit outside in the warm sun, or let it air dry while sitting in the sun (the sun isn't necessary to activate sun-in, the heat of a blowdryer alone will do the job)
- If opt for using only a blowdryer to activate the sun-in, you can focus on drying just the pieces you sectioned out, versus your whole head
- Repeat these steps, selecting alternate sections of hair, until the desired lightness is achieved
Will lightening spray work on hair that has been previously colored (lightened or darkened)?
This type of product will usually not work on hair that has been previously colored. On hair that has been darkened, it will likely not work at all. On hair that has been lightened, it may lighten the hair a bit more, but you risk damaging your strands by applying a lightener over pieces that have already been lightened (see this video by YouTuber Leda Fazal. Sun-in works best on hair that is between a chocolate brown and a caramel brown, or lighter, that has never been colored.
Will it lighten red hair?
Yes, it will lighten naturally red hair between a deep copper and a light auburn.
What will it do to gray hair?
Sun-in is a hair lightener, not a colorant, so it will not do much to gray hair. However, it may take any yellowish tints out during the lightening process.
Does it need sunlight to work?
These types of products are usually heat activated. The sun or a blowdryer will start the lightening process.
Will hair fade back to its natural color eventually after applying sun-in?
Only new hair that grows in will be your original color. Any pieces that have been colored with sun-in are permanently altered, and may even continue to lighten a bit over time.
What are some of the unexpected repercussions of using lightening sprays?
The obvious pros of sun-in sprays are that they're cost and time-effective. Some of the less-known potential cons include:
- The difficulty of controlling your final tone. Using more sun-in doesn't necessarily change the color you end up with. Generally these products lean towards warmer tones, which can be especially apparent in dark hair.
- If you have already lightened your hair before using sun-in, there is a risk of severe discoloration and damage if the product is overused.
- Many hairdressers will not apply professional coloring products over hair that has been treated with sun-in because some sun-in formulas can have chemical reactions with professional products. For example, hair foils can swell in an abnormal and unpredictable way. When hair professionals are unwilling to apply color in this scenario, the outcome of an unwanted sun-in color becomes even more permanent because the client is unable to professionally correct the color mistake.
- Some sun-in formulas have a high pH level, leading to them being overly acidic. This can dry your hair out and lead to damage.
Check out the video below by YouTuber Leda Fazal to get more insights on the potential cons.