While commonly used in salons to speed up the process, using heat when coloring hair is not totally necessary and can potentially cause damage.
Understanding Heat and Hair Coloring
Hair coloring is a chemical process where pigments are either deposited onto the hair shaft or lifted from it (in the case of lightening). Heat is sometimes applied during this process.
Why Heat is Sometimes Used
- Speed: The primary reason heat is used in professional settings is to accelerate the chemical reaction of the hair dye or bleach. This can significantly reduce processing time, allowing stylists to see more clients.
The Risks of Using Heat
Despite its use for speed, applying heat during chemical processes like coloring or bleaching comes with potential drawbacks for your hair's health.
As dermatologist Dr. Rachel Nazarian notes, "Heat, along with bleaching, strips the natural oils and hydrators and can thin the hair—increasing the risk of breakage, splitting, and brittleness of the follicle."
This highlights that heat, especially when combined with the chemical action of hair color or bleach, can contribute to:
- Moisture Loss: Stripping away essential natural oils and hydration.
- Weakening: Making the hair thinner and more susceptible to damage.
- Increased Risk of Breakage: Leading to splits and brittleness.
Is Heat Necessary?
Based on expert opinion, the use of heat during coloring is a common technique for efficiency but it's not an essential step for the color to develop. The chemical process will occur on its own over time at room temperature, albeit more slowly.
Choosing not to use heat, or keeping its application minimal, can potentially help preserve the hair's natural moisture and reduce the risk of damage, especially for those with already fragile or damaged hair.
