Changing your hair color can be a fun way to refresh your look, cover gray hair, or try something different. But with so many formulas available, choosing a product involves more than simply picking a shade.
Different hair color products work in different ways. Some deposit color on or near the surface of the hair, while others chemically alter the hair to create longer-lasting results. The ingredients and process involved can also affect the hair shaft and, in some people, irritate the skin or trigger an allergic reaction.
Understanding the main types of hair color, following the manufacturer's directions, and caring for your hair afterward can help make the coloring process safer and easier on your hair.
What Are Hair Coloring Products?
Hair color products include permanent, demi-permanent, semi-permanent, and temporary dyes, as well as products used to bleach or lighten hair.
- Permanent hair color typically uses an oxidative process to create color inside the hair shaft, producing results designed to last as the hair grows out.[1]
- Demi-permanent and semi-permanent colors generally provide less permanent results and gradually fade with washing. The way they deposit color varies depending on the particular formula.
- Temporary hair color mainly coats the outside of the hair and usually washes away relatively quickly.
- Bleaching products lighten hair by chemically breaking down its natural pigment. Because bleaching alters the structure of the hair, repeated or aggressive bleaching can also make hair more porous, dry, and prone to breakage.
The right option depends on the result you want, how long you want it to last, and the current condition of your hair.
How to Choose Hair Color Products Safely
Before using a new product, read the label carefully and follow the manufacturer's instructions.
Important precautions include:
- Follow the product's instructions for a skin allergy test before coloring your hair.
- Repeat the recommended allergy test each time you use hair dye, even if you have used the same product before without a problem.
- Do not leave the product on longer than directed.
- Avoid applying dye to an irritated, damaged, or broken scalp.
- Wear the gloves supplied with the product.
- Keep hair dye away from your eyes.
- Do not mix different hair dye products unless the instructions specifically direct you to do so.
Following these precautions cannot eliminate every possible reaction, but it can reduce unnecessary exposure and help you use the product as intended.
Ingredients That May Cause Reactions
Some hair coloring products contain ingredients that may trigger allergic reactions in sensitive individuals. One ingredient commonly found in many permanent hair dyes is para-phenylenediamine (PPD), which has been associated with allergic reactions in some people.[2]
Possible signs of a reaction may include:
- Redness
- Itching
- Burning
- Swelling
- Rash
Even if you've used hair dye before without experiencing problems, allergic reactions can develop over time. Following the manufacturer's patch test instructions, when recommended, may help identify a reaction before applying the product more broadly.[3]
Caring for Your Hair After Coloring
Hair coloring, particularly bleaching or repeated chemical treatments, may increase dryness and make hair more prone to breakage.
To help care for color-treated hair:
- Use hair care products formulated for color-treated hair if they suit your hair type.
- Limit heat styling when possible.
- Limit prolonged sun exposure, which may help reduce additional dryness and color fading.
- Detangle hair gently to help reduce breakage.
- Avoid repeated chemical treatments within a short period.
These practices may help reduce stress on the hair and improve manageability over time.[4]
When Should You See a Dermatologist?
If you experience severe itching, burning, swelling, blistering, or a widespread rash after using hair coloring products, discontinue use and seek medical advice promptly.
If you've experienced previous reactions to hair dye or have concerns about possible allergies, a dermatologist may recommend allergy testing before you color your hair again.
Key Takeaways
- Different hair color products vary in how they deposit or alter color and how long the results last.
- Always read and follow the manufacturer's instructions before coloring your hair.
- Follow the recommended skin allergy test before each use, even if you have previously used the product without a reaction.
- PPD, which is found in many permanent hair dyes, can cause allergic reactions in some people.
- Bleaching and repeated chemical processing can make hair drier and more prone to damage.
- Gentle aftercare can help protect color-treated hair and reduce additional breakage.
Choosing the right type of hair color and using it as directed can help you achieve the result you want while reducing unnecessary stress on your hair and scalp.
References
[1] https://www.compoundchem.com/2015/05/14/hair-dyes/
[2] https://pmc.ncbi.nlm.nih.gov/articles/PMC5261844/
[3] https://www.healthline.com/health/hair-dye-allergy
[4] https://campus.edu/blog/cosmetology/how-to-care-for-your-hair-after-coloring