How To Use Blue Shampoo For Brassy Hair | Tone Without The Tint

Blue shampoo neutralizes orange and copper tones in brassy brown hair in about 3–5 minutes.

For the full breakdown, see our best Brassy Hair Shampoo guide.

Brassy hair happens to nearly everyone with lightened brown locks. The warm orange that shows up weeks after a salon visit is the underlying pigment surfacing as color fades. Blue shampoo counters that heat with a simple color-wheel trick: blue sits opposite orange, so the pigments cancel each other out instead of layering on more dye. When you use blue shampoo for brassy hair correctly, it restores a cooler, richer brunette shade between salon visits, without a trip back to the chair.

What Does Blue Shampoo Actually Do?

Blue shampoo deposits blue-violet pigments onto the hair strand to neutralize warm orange, red, and copper tones. Where purple shampoo targets yellow brassiness on blonde hair, blue shampoo is formulated for brunettes, highlighted brown hair, and balayage that pulls orange after lightening.

If your brassiness reads more yellow than orange, purple shampoo is usually the better match. The two aren’t interchangeable, and using the wrong one means the toner misses the tone you’re trying to fix.

How Often Should You Use Blue Shampoo?

About once a week is the common recommendation for maintaining a cool brunette shade. Some sources suggest once or twice weekly depending on how fast your color fades. Daily use is not advised.

Overuse is the fastest way to trade one problem for another. Too much blue pigment can leave an unwanted blue or green cast, especially on lighter or more porous sections of hair. The pigment is also drying, so a moisturizing conditioner after each wash keeps the hair from feeling brittle.

The Step-By-Step Application

Apply blue shampoo to wet hair, concentrating on the areas that look most orange. Massage it in and let it sit — 2–3 minutes for mild toning, 3–5 minutes if the brassiness is stubborn. Rinse thoroughly and follow with conditioner.

Instructions vary by product and formula strength, so the specific bottle directions should always win over a general routine. L’Oréal Paris notes that results depend on following that product’s guidance, and Matrix’s styling experts emphasize the same point about reading the label first.

What To Watch For

Two side effects come up most often: dryness and an unwanted cool tint. Both trace back to leaving the shampoo on too long or using it too frequently. If your hair takes on a blue or green tinge, stop using the shampoo and let the pigment fade with regular washing.

If you’re choosing a formula for the first time, our roundup of tested options for brassy hair shampoo compares strength, tone results, and how each one performs on real brunette hair.

Skip the shampoo entirely if your hair hasn’t been lightened or colored. Virgin brunette hair rarely turns brassy because there’s no lifted pigment to expose. Blue shampoo on unprocessed brown hair does little except add unnecessary dryness.

For hair that’s heavily damaged or overly porous, L’Oréal Paris’s guide to blue shampoo recommends extra care with timing, since porous strands absorb pigment faster and hold it longer.