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Can you add protein color filler to hair dye?

Hair color fillers, also known as protein fillers or protein reconstructors, are an important part of coloring hair for many people. Protein fillers help prepare the hair to accept color more evenly by filling in gaps or pores in damaged areas. Some people add protein filler to their dye mixture, while others do a separate protein filler treatment before coloring their hair. Here’s what you need to know about adding protein fillers to hair dye.

What are protein fillers?

Protein fillers are conditioning treatments that contain protein, typically hydrolyzed wheat or soy protein. When applied to the hair, the protein molecules fill in gaps or holes in the cuticle layer of the hair strand caused by chemical damage or mechanical damage like heat styling. This helps create a smooth, sealed cuticle surface so the hair can reflect light better and hold color more evenly.

Some main benefits of protein filler include:

  • Fills in damaged areas so hair dye will deposit evenly
  • Reduces porosity differences in hair for more uniform color results
  • Strengthens hair by temporarily patching holes in cuticle layer
  • Adds moisture and softness as a conditioning treatment

Protein fillers are especially helpful for people with overprocessed or porous hair. The damaged areas soak up more dye, resulting in an uneven final color. Using a protein filler first equalizes the porosity differences so the color applies true to tone from roots to ends.

When to use protein filler before coloring

In general, it’s a good idea to use a protein filler before coloring treated or damaged hair. Specific situations when protein filler is recommended:

  • Bleached hair – fills in gaps in very porous hair for even dye absorption
  • Chemically straightened hair – seals cuticle after harsh straightening process
  • Colored hair being re-colored – evens out old dye absorption for new color
  • Damaged, overprocessed hair – fills in broken cuticle layer
  • Perm or relaxed hair – adds strength after chemical processing
  • Heat styled hair – seals cuticle gaps caused by hot tools

For people with healthy, virgin hair, a protein filler may not be necessary before coloring as the cuticle layer should be intact.

Can you add protein filler directly to dye?

Some hair color kits actually include a packet of protein filler or reconstructor that you add directly to the color. This allows the protein to penetrate within the hair strand along with the dye molecules. However, there are a few drawbacks to mixing protein filler into dye:

  • It dilutes the color formula, which may result in less vibrant results
  • The protein can’t work as long on the hair to properly fill gaps when deposited at the same time as dye
  • Protein filler works best at room temperature but dye needs warmth to process fully
  • Some proteins can react adversely with dye chemicals like peroxide

Because of these potential issues, most professional colorists recommend doing a protein filler step separately from coloring.

How to use a protein filler before dyeing

Here are some tips for effectively using protein filler before coloring your hair:

  • Do a protein filler treatment 1-2 days before coloring hair. This gives time for it to properly fill cuticle gaps.
  • Choose a protein filler product specifically designed for hair coloring. Popular options are Redken Equalizer or Sally Beauty Generic Value Protein Filler.
  • Apply protein filler to shampooed, towel-dried hair. Comb through evenly from roots to ends.
  • Leave on for 5-15 minutes then rinse out thoroughly.
  • Follow with a conditioning treatment to add moisture.
  • Let hair dry completely before applying color.
  • Use a brush to evenly apply hair dye once hair is protein filled.

Doing a separate protein filler step 1-2 days before coloring allows the treatment to work into the hair properly. Then color applies true to tone for beautiful results!

Does protein filler damage hair?

Protein fillers are conditioning treatments meant to strengthen and repair hair, not damage it. However, it is possible to overdo protein, leading to protein overload.

Signs of protein overload include:

  • Hair that feels stiff, brittle, or straw-like
  • Hair that is tangled and dry
  • Loss of curl pattern
  • Increased breakage

This happens when excessive protein builds up on the hair over time, causing rigidity rather than flexibility. To avoid protein overload:

  • Use protein filler no more than 1-2 times per month
  • Alternate protein treatments with moisturizing deep conditioning
  • Rinse filler out thoroughly after recommended processing time
  • Adjust protein filler frequency based on your hair’s needs

When used properly 1-2 times a month, a protein filler treatment can strengthen and prepare hair for coloring without causing protein overload damage.

DIY protein hair fillers

Protein hair fillers can also be made at home using simple ingredients. Here are some popular DIY protein treatment recipes:

Gelatin protein hair treatment

  • 1 packet unflavored gelatin powder
  • 1 cup hot water

Mix gelatin powder with hot water until dissolved. Apply evenly to shampooed, towel-dried hair. Leave on for 10 minutes then rinse out and condition. The gelatin provides a protein boost to fill gaps in the damaged cuticle layer.

Mayonnaise hair protein mask

  • 1/2 cup mayonnaise
  • 1 egg
  • 1 teaspoon olive oil or argan oil

Whisk together mayonnaise, egg, and oil. Apply to damp hair and let sit 30-60 minutes. Rinse out thoroughly. The egg protein helps strengthen and protect hair.

Banana protein hair mask

  • 1 overripe banana
  • 1 tablespoon coconut oil
  • 1 tablespoon honey

Mash banana into a smooth paste. Mix in coconut oil and honey. Apply to clean, damp hair and allow to penetrate for 30 minutes. Rinse out and shampoo. Banana is rich in vitamins, minerals, and proteins that nourish hair.


Here are the key takeaways about using protein filler with hair dye:

  • Protein fillers prepare damaged hair for more even color results by filling gaps in cuticle layer
  • Ideal to use a protein filler 1-2 days before coloring damaged or porous hair
  • Mixing protein filler directly into dye may dilute color results
  • DIY protein treatments can be made with gelatin, eggs, banana, or other protein-rich ingredients
  • Avoid overuse of protein filler to prevent protein overload causing brittle hair

Be sure to do a patch test when using any new hair products like protein fillers or dyes. With proper use, a protein filler can be a helpful step before coloring hair to ensure beautiful, shiny, evenly saturated color.


In summary, protein fillers can be a useful addition to your hair coloring routine, especially if you have damaged or very porous hair. A protein treatment 1-2 days before coloring fills in gaps in the cuticle layer so dye absorbs evenly from roots to ends. While some dye kits contain built-in protein fillers, most experts recommend doing a separate protein step first. This allows the protein to penetrate the hair properly without diluting or interacting with the color. With the right prep using protein filler before dyeing, you can achieve rich, vibrant, lasting color results. Alternate with moisturizing deep conditions and adjust protein use based on your hair’s needs. And always do a patch test before using any new hair products. With some planning and TLC, protein fillers can help you color your locks with beautiful results!