Can I bleach after using henna, indigo, buxus or cassia?
If you have only used pure plant dyes and not compound dyes ("henna" products that come in different colors, premixed) in which there may be metallic salts that react badly with ammonia and peroxide, then moderate use of bleach after henna, etc, will not destroy your hair. However, plant dyes don't bleach out as easily as chemical hair dyes, so the color you end up with may not be what you expect or hope for. It's best to do a strand or hairball test with the bleach before you do your whole head.
Bleach on hennaed hair will lighten the shade of red/orange, but quite often it can't eliminate all the orange color completely without significant damage. For example, light brown hair treated with 2 or 3 full hennas lightened only to bright carrot orange after 45 minutes of 40 vol peroxide with bleach activator. Virtually all the hair's natural color had been lightened away at that point, leaving only the henna. Further bleaching made the hair start to get sticky and dissolve.
Bleaching after indigo use is never advised because bleach cannot lift indigo. It will remove all the other color in your hair, leaving the indigo green intact. This means your hair will be permanently colored green and may not be correctable with any type of hair dye, plant-based or not.
Bleaching a hairball treated with henna and a 45-minute application of buxus yielded a light ash blonde, so strand test first as always, but it can work.
Bleaching hair treated with cassia is okay; no undesirable results have been reported.Return to FAQ Page