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What does clarifying shampoo do? Buildup, colour, and how often
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Clarifying shampoo is a stronger cleanser made to remove what an everyday shampoo leaves behind: styling products, silicones, oils, and residue from hard water or pool water. It is meant for occasional use. For most people who use styling products, once or twice a month is enough, and people who use little product may not need it at all.
This post covers what clarifying shampoo removes, how to tell whether you need it, how often to use it, and what it does to colour-treated hair. For the basics of a normal wash, see our guide on how to wash your hair.
What clarifying shampoo removes
Everyday shampoos are built to clean the scalp without taking too much oil from the hair. Over time, that gentler cleaning can leave a layer behind. Styling products are the main source. A review of shampoos in the Indian Journal of Dermatology explains that the polymers in styling products build up on the hair shaft with continued use and make the hair look rough and dull and feel harsh. To remove them, the review says, a deep-cleaning shampoo uses a strong detergent such as a lauryl sulfate.
Some ingredients are harder to shift than others. A review of hair cosmetics in the International Journal of Trichology notes that some polymers build up on the hair and bind to the cleansing agents in shampoo, forming a layer that resists washing. This is one reason a regular shampoo can stop getting hair fully clean after weeks of heavy product use.
Other sources of buildup include:
- heavy conditioners, leave-ins, creams and oils,
- dry shampoo, which is a powder that stays on the scalp until it is washed out,
- minerals from hard water,
- chlorine and copper from pool water.
Cleveland Clinic lists gels, hairspray, creams and serums as products that build up on the hair and scalp and can make hair feel oily.
What makes it stronger
The difference is mostly in the cleanser. Clarifying shampoos usually rely on a strong cleansing agent near the top of the ingredient list, often sodium lauryl sulfate. The Indian Journal of Dermatology review describes lauryl sulfates as strong cleansers that work in both hard and soft water and produce a rich lather, and it recommends them for oily hair with the warning that hair washed with them needs careful conditioning.
That strength has a cost for the hair surface. The International Journal of Trichology review explains that strong cleansers of this type can add to the negative electrical charge on the hair surface and increase frizz and friction. This is why hair can feel squeaky and tangle more straight after a clarifying wash, and why conditioner, which carries a positive charge, smooths it again.
Labels help less than you would hope. "Clarifying", "detox", "deep cleansing" and "purifying" are marketing names with no fixed definition. Read the ingredient list instead: a sulfate or another strong cleanser in the first few ingredients tells you more than the name on the front.
Related readDoes heat protectant actually work? What it does and where it stopsSigns you need a clarifying wash
Buildup has a feel. Hair looks dull even after washing. It feels coated, waxy or heavy, and loses volume at the roots. Conditioner seems to stop working, and styling products that used to hold a shape now leave the hair limp or sticky. Our post on why hair feels waxy after washing has a two-minute test that separates product residue from the other common causes.
Dry hair can feel rough and dull too, so it is worth ruling that out. Dry hair usually feels rough and light, and it drinks up conditioner. Hair with buildup feels smooth in a coated way and seems to push conditioner off. If the hair is dry, a clarifying shampoo will make it drier.
How often to use it
Cleveland Clinic's advice is that people who use a lot of styling products should consider a clarifying shampoo one to two times per month. The Indian Journal of Dermatology review describes deep-cleaning shampoos as typically used once weekly.
Those two figures cover most people. A practical way to choose:
- Once a week if you use strong styling products every day, use dry shampoo most days, or swim several times a week.
- Once or twice a month if you use some styling products or oils most weeks.
- Only when the signs appear if you use little product and your hair feels clean after a normal wash.
Clarifying shampoo does not suit daily use. The strong cleanser that removes buildup also removes the natural oil that keeps the hair surface smooth. The same review notes that over-cleaned hair becomes harsh, rough and dull, with frizz, and tangles more easily.
How to use it
Wet the hair fully. Apply the clarifying shampoo to the scalp and work it in with your fingertips, then let the lather run down the lengths as you rinse. If the buildup is heavy, wash a second time. Rinse for longer than usual, because leftover shampoo adds to the problem you are trying to fix.
Then condition. This step matters more after a clarifying wash than after any other. Put conditioner on the mid-lengths and ends, leave it for the time on the label, and rinse. Hair that is dry, curly or bleached may need a deep conditioner or mask instead.
If you use two shampoos in one wash, the clarifying one goes first. The American Academy of Dermatology describes this order for curly hair with buildup: use a clarifying shampoo before the moisturising shampoo, then condition all of the hair.
Related readDo hair vitamins actually work? What the evidence saysHard water and swimming
Hard water carries dissolved minerals, mostly calcium and magnesium. Research on what those minerals do to hair is small and mixed. One study of hair from 15 volunteers found that a month of hard water treatment made no measurable difference to the strength or stretch of the hair. Many people with hard water still notice hair that feels dull and coated, and a clarifying wash is a simple test: if the hair feels cleaner afterwards, residue was part of the problem. Our post on hard water and your haircut covers what hard water does to hair and when a shower filter makes more sense than a stronger shampoo.
Pool water is a second job for a clarifying shampoo. The American Academy of Dermatology explains that chlorine dissolves the fats that coat the hair shaft, and can combine with copper in the water and be absorbed by the hair, turning it green. Its advice is to rinse the hair straight after swimming, then wash it with a shampoo made for swimmers and follow with a deep conditioner. Swimmers' shampoos are clarifying shampoos aimed at chlorine and copper. The Academy also suggests putting oil or a leave-in conditioner on the hair before swimming, as a barrier between the hair and the chlorine.
Clarifying shampoo and colour-treated hair
Clarifying shampoo will speed up the fading of dyed hair. How much depends on the type of colour, how fresh it is, and how often you clarify.
It helps to know how colour leaves the hair. A study on colour fading in the Journal of Cosmetic Science found that fading of permanent hair colour during washing happens mainly because the dye dissolves into water, and that the type of cleanser in the shampoo is one of the factors that changes how fast. Every wash removes some colour. A strong cleanser removes more per wash.
So for coloured hair:
- Wait a few washes after a colour appointment before clarifying.
- Clarify only when buildup is a real problem, and less often than you would on uncoloured hair.
- Be most careful with colour that only coats the outside of the hair. The International Journal of Trichology review notes that demi-permanent dyes fade after 10 to 15 shampoos, or earlier, while permanent dye sits inside the hair.
- Condition after every clarifying wash, since coloured and bleached hair is more porous and loses moisture faster.
Some brands sell colour-safe clarifying shampoos with milder cleansers. They fade colour less and also remove less buildup. On hair that is both coloured and heavily coated, one full-strength clarifying wash followed by a gentle routine often does less harm than weeks of washes that never get the hair fully clean.
If your hair has turned brassy or green from pool water, a clarifying shampoo may help with the green, since it comes from copper. Brassiness in blonde hair is a colour question, and a colourist is the right person to ask.
What clarifying shampoo does not fix
Clarifying shampoo removes things that sit on the hair and scalp. Conditions of the scalp itself need their own treatment.
Dandruff is the most common mix-up. A clarifying wash can clear flakes for a day or two, but the flakes come back because the cause is still there. The American Academy of Dermatology recommends shampoos with specific active ingredients for dandruff: zinc pyrithione, salicylic acid, sulfur, selenium sulfide, ketoconazole or coal tar. If dandruff continues after using one of those, or becomes severe, the same page advises seeing a dermatologist, who can check for conditions such as seborrheic dermatitis or psoriasis.
An oily scalp is a second case. Clarifying removes oil and residue for that wash, and it does not change how much oil the scalp produces. Regular washing with an everyday shampoo usually does more for an oily scalp than an occasional strong one. Our guide on oily roots and dry shampoo covers that routine.
Dry, brittle hair is the third. If hair is rough and breaks easily and there is no sign of buildup, the answer is gentler washing and more conditioning. A stronger cleanser will make it worse.
A scalp that itches, burns, scales or becomes red after any shampoo is a reason to stop using that product and, if it continues, to see a dermatologist.
Common questions
What's the purpose of clarifying shampoo?
Clarifying shampoo removes buildup that a regular shampoo leaves behind, such as styling products, silicones, oils and residue from hard water or pool water. It uses a stronger cleanser than an everyday shampoo, so it is meant for occasional use when hair looks dull, feels coated or stops responding to products.
How often should you do a clarifying shampoo?
For most people who use styling products, once or twice a month is enough, which is the range Cleveland Clinic gives. People who use heavy products daily or swim often may need it weekly. If you use little product and your hair feels clean after washing, you may not need it at all.
Does clarifying shampoo remove hair dye?
It can fade dye faster than a gentle shampoo, especially semi-permanent colour and fresh colour. It does not strip permanent colour out of the hair in one wash. Colour fades mainly because dye dissolves into water during washing, and a stronger cleanser adds to that.
Is clarifying shampoo safe for colored hair?
It is safe to use occasionally, and it will speed up fading. Wait at least a few washes after colouring, use it only when buildup is a real problem, and follow it with conditioner. Some brands sell colour-safe clarifying shampoos, which use milder cleansers and remove less buildup as a result.
Does clarifying shampoo damage hair?
Used occasionally, it does not damage healthy hair, though it can leave hair dry and rough straight after the wash. Used too often, it removes the natural oils that keep hair smooth, which leads to dryness, frizz and tangles. Always follow a clarifying wash with conditioner on the lengths.
Does clarifying shampoo help with dandruff?
It can remove flakes and oil for a day or two, but it does not treat the cause of dandruff. Dandruff shampoos work because of active ingredients such as zinc pyrithione, selenium sulfide, ketoconazole, salicylic acid or coal tar. If flaking continues after using one of those, see a dermatologist.
Does clarifying shampoo help with hard water?
It helps with some of it. A clarifying shampoo removes the product residue that minerals tend to cling to, and many contain ingredients that bind minerals. A shampoo sold for hard water or swimmers is designed for this job, and a shower filter reduces the minerals reaching the hair in the first place.
Will clarifying shampoo remove chlorine?
It helps. The American Academy of Dermatology recommends rinsing hair straight after swimming and then washing it with a shampoo made for swimmers, followed by a deep conditioner. Swimmers' shampoos are a type of clarifying shampoo aimed at chlorine and the copper that turns light hair green.
Can clarifying shampoo be used daily?
It is not meant for daily use. A clarifying shampoo removes more oil than hair needs to lose every day, and daily use leaves most hair dry, rough and frizzy. Use a regular shampoo for daily washing and keep the clarifying one for when buildup appears.
Is clarifying shampoo good for curly hair?
Yes, used occasionally. Curly hair routines often rely on heavy creams, gels and oils, which build up over time. The American Academy of Dermatology suggests using a clarifying shampoo before the moisturising shampoo when curly hair has buildup, and then conditioning all of the hair.
Is clarifying shampoo good for oily hair?
It can help oily hair that also carries product residue, and it can feel fresh after the wash. It will not reduce how much oil the scalp makes, so it is a poor choice as a daily shampoo. For an oily scalp, frequent washing with a regular shampoo usually works better.
Do clarifying shampoos have sulfates?
Most do. The strong cleansers used to remove buildup are often sulfates such as sodium lauryl sulfate. Sulfate-free clarifying shampoos exist too, using other cleansers, and they tend to be milder, so they remove buildup more slowly over several washes instead of in a single pass.
Is clarifying shampoo the same as detox shampoo?
Often the two do the same job. Detox is a marketing name with no fixed definition, and many detox shampoos are clarifying shampoos with a different label. Check the ingredients for a strong cleanser near the top of the list to see how much the product will remove.
Should clarifying shampoo be used first?
Yes, if you use two shampoos in one wash. Use the clarifying shampoo first to remove buildup, then a regular or moisturising shampoo if you want, then conditioner. The American Academy of Dermatology describes this order for curly hair with product buildup, so the moisturising step works on hair that is already clean.
Do you really need clarifying shampoo?
Only if you have buildup. People who use styling products, dry shampoo, heavy conditioners or oils, or who swim or live with hard water, usually benefit from it now and then. People who use little product and whose hair feels clean after a normal wash can skip it.
Will clarifying shampoo lighten hair?
It does not change natural hair colour, because it contains no bleach. On dyed hair it can fade the colour, which can make the hair look lighter. Hair that was dull from buildup may also look brighter after a clarifying wash, which is a different effect from actual lightening.
Is clarifying shampoo good for low porosity hair?
Often, yes. Low porosity hair takes in products slowly, so creams and oils tend to sit on the surface and build up. An occasional clarifying wash clears that layer so the next conditioner can reach the hair, rather than sitting on top of the old buildup.
Does clarifying shampoo remove toner?
It can fade toner faster. Toner is a thin layer of colour that fades with washing, and a strong cleanser removes more of it each time. If you have just been toned, ask your colourist how long to wait before clarifying, since that timing varies by the toner used.
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