Is It Safe to Bleach Already Bleached Hair?

What is hair bleaching and is it safe?

Oxidized melanin loses its color, making the hair look lighter. Bleaching significantly damages your hair. Whether you should rebleach your bleached hair depends on the health of your hair before and after bleaching.
Oxidized melanin loses its color, making the hair look lighter. Bleaching significantly damages your hair. Whether you should rebleach your bleached hair depends on the health of your hair before and after bleaching.

They say, “Life is too short for boring hair.” In today’s era of social media and influencers, people do not hesitate to try new and cooler ways to get a new look for their hair. Bleached hair has always fascinated people because of the way it transforms their look. Be it highlights or getting the flaxen blonde look, bleaching has and will forever be in vogue. Highlights often give you a sun-kissed, beach boy/beach girl look, so they are always popular.

The color of your hair is determined by the presence of a dark pigment called melanin produced by a special type of cell called a melanocyte. The chemicals contained in the bleach solution oxidize the melanin pigment in your hair to lighten them. One of the most common oxidizing agents used in bleach is hydrogen peroxide. Oxidized melanin loses its color, making the hair look lighter. There are two types of melanin pigments in your hair: eumelanin and pheomelanin. Bleach mainly oxidizes eumelanin, the pigment that makes the hair look black. This enhances the appearance of pheomelanin, the pigment that gives hair a reddish shade. Thus, bleached hair may look reddish orange in people with dark hair. Besides the oxidizing agent (hydrogen peroxide), bleaching solutions also contain ammonia, which produces an alkaline environment necessary for peroxide to penetrate the hair. Darker hair may need more time and more bleaching sessions than lighter hair to achieve a particular shade after bleaching.

Whether you should rebleach your bleached hair depends on the health of your hair before and after bleaching. Bleaching significantly damages your hair. For the oxidizing agent to come in contact with melanin, the bleaching solutions open the shaft of your hair (the part of the hair above the hair roots). This damages the protective layer around your hair, the cuticle. Damage to the cuticle makes your hair turn weak, frizzy and lusterless. The damage is comparatively more when bleaching is not done by a professional or under a professional’s guidance. Dark hair or coarse hair generally needs multiple sessions to achieve the desired shade. If you wish to get a hair color that is three or more shades lighter than your present hair shade, you may have to go for multiple bleaching sessions. This can be truly damaging for your hair. Multiple bleaching sessions can turn your hair lifeless, increase hair breakage and cause significant hair thinning. If your hair is already dry and dull, you should put off bleaching until your hair is sufficiently moisturized. Experts suggest you wait at least four weeks between two bleaching sessions. This allows your hair to regain its moisture and strength to withstand another bleaching session. Always follow professional guidance before you bleach or color your hair.

Before going for a bleaching session, give your hair at least 15 to 30 days of pampering during which you moisturize your hair well using coconut, argan or olive oil. You can also use a keratin mask at home or in a salon. Coconut oil protects your hair against the damaging effect of bleaching solutions. It also does not interfere with the action of bleach on your hair. Thus, have a nice coconut oil massage, and then go for the bleaching session without washing your hair afterwards.

References
Medscape Medical Reference

Science Project


Dermatology Consultants