Shampoo for green hair: why hair turns green and how to fix it
Green hair is caused by copper ions in the water that cling to porous, bleached, or light-colored hair. To prevent green discoloration, you need a sulfate-free shampoo that cleanses gently without opening the cuticle further, combined with a routine that reduces your hair’s exposure to mineral-rich water.
Green hair is a more common problem than many people think, especially for blonde, gray, or chemically treated hair. It is not a sign of dirty hair, but rather that the hair’s porous cuticle absorbs copper from the water. The right shampoo and routine can both prevent and reduce green discoloration.
Why does hair turn green?
Green hair is caused by copper ions that occur naturally in tap water and in chlorinated swimming pool water. When copper oxidizes on contact with chlorine, copper oxide forms, which is green. Porous hair, especially bleached, dyed, or damaged hair with an open cuticle, readily absorbs the copper ions. Harsh sulfates make the problem worse by opening the cuticle further with every wash.
Learn more about caring for blonde hair in our guide to shampoo for blonde hair.
How can you prevent green hair?
The most important step is to reduce your hair’s porosity so it absorbs fewer copper ions. A sulfate-free shampoo that cleanses with a gentle coconut-derived surfactant won’t unnecessarily open the cuticle. Conditioner after every wash smooths the cuticle and reduces absorption. Always finish with a cool rinse to close the cuticle.
FOAM’s Rice Serenity shampoo bar is fragrance-free and especially gentle, making it suitable for sensitive, porous hair that is prone to absorbing color. Learn more about choosing the right one in our complete shampoo guide.
What should you do if your hair is already green?
If your hair has already turned green, a deep-cleansing treatment can help dissolve copper deposits. Tomato juice or apple cider vinegar diluted in water are traditionally used to neutralize green tones, but results vary. The safest option is to consult a hairdresser for professional treatment. Above all, switch to a sulfate-free shampoo to prevent the problem from returning.
The Editor's Note: Wet your hair with tap water before jumping into a swimming pool. Hair that is already saturated with water absorbs fewer copper ions from pool water. It’s a simple preventive step that makes a big difference.
Learn more about caring for gray hair in our guide to shampoo for gray hair.
Prevent green hair: what to do
| Do | Avoid |
|---|---|
| Sulfate-free shampoo with a gentle coconut-derived surfactant | SLS and SLES, which open the cuticle |
| Condition after every wash to smooth the cuticle | Skipping conditioner |
| Finish with a cool rinse | Hot water, which keeps the cuticle open |
| Wet your hair with tap water before swimming | Jumping into the pool with dry hair |
| Deep conditioning treatment to reduce porosity | Bleaching without aftercare |
Learn more about caring for damaged and porous hair in our guide to shampoo for damaged hair.