Shampoo for green hair: why hair turns green and how to fix it
Green hair is caused by copper ions in the water becoming trapped in porous, bleached, or light-colored hair. To counteract green discoloration, you need a sulfate-free shampoo that cleanses gently without opening the cuticle layer 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 realize, especially for blonde, gray, or chemically treated hair. It is not a sign of dirty hair, but rather that the hair’s porous cuticle layer 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 swimming pool water treated with chlorine. When copper oxidizes on contact with chlorine, copper oxide is formed, which is green. Porous hair, especially bleached, colored, or damaged hair with an open cuticle layer, absorbs copper ions easily. Strong sulfates worsen the problem by opening the cuticle layer further with every wash.
Read more about how to care for blonde hair in our guide to shampoo for blonde hair.
How can you prevent green hair?
The most important step is to reduce the hair’s porosity so that it absorbs fewer copper ions. A sulfate-free shampoo that cleanses with a gentle coconut-derived surfactant does not unnecessarily open the cuticle layer. Conditioner after every wash smooths the cuticle layer and reduces absorption. Always finish by rinsing with cold water to close the cuticle layer.
FOAM’s Rice Serenity shampoo bar is fragrance-free and especially gentle, making it suitable for sensitive and porous hair that is prone to color absorption. Read more about how to choose 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 may help dissolve copper deposits. Tomato juice or apple cider vinegar diluted in water is traditionally used to neutralize green tones, but the effect varies. The safest option is to consult a hairstylist for professional treatment. Above all: switch to a sulfate-free shampoo to prevent the problem from recurring.
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 is a simple preventive step that makes a big difference.
Read more about how to care for gray hair in our guide to shampoo for gray hair.
Prevent green hair: follow these steps
| Do | Avoid |
|---|---|
| Sulfate-free shampoo with a gentle coconut-derived surfactant | SLS and SLES, which open the cuticle layer |
| Use conditioner after every wash to smooth the cuticle layer | Skipping conditioner |
| Finish with a cold-water rinse | Hot water, which keeps the cuticle layer 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 |
Read more about how to care for damaged and porous hair in our guide to shampoo for damaged hair.