SOLVENT
Water
- solvent
The base of almost every rinse-off and cream hair product. It carries everything else and is normally the first ingredient on the label.
- products in our library
- 3069
- of researched products
- 79%
- on the label, in our shampoos
- usually #1
- most common in
- Shampoo
- in water
- Water-soluble
At a glance
Four named levels, read from this ingredient’s chemical class, its charge, its solubility, or where it sits on the labels we have. More dots means more of the property named — never “better”.
How much of it is left on hair between washes.
What it takes to get it off the hair again.
How fast it leaves after the product is applied.
What is still on the hair once it has evaporated.
| Property | Level | Out of |
|---|---|---|
| Buildup risk | Low | 1 of 5 |
| Rinse-out behaviour | Rinses clean | 5 of 5 |
| Drying speed | Slow | 1 of 5 |
| Residue | Minimal | 2 of 5 |
What it does for a formula
What Water does
The general function first, then how the role changes by product type where we have researched it.
What everything else is dissolved in before it reaches your hair.
Water alone removes it, so it does not accumulate between washes.
Charge
Charge is not recorded for this ingredient.
Solubility
Rinses out with water alone — it does not accumulate on hair between washes.
Where it appears
Where it appears
One row per product category in our library: how many products list it, what share of that category that is, and where it typically sits on the label.
| Product type | How common | Typical position on label ? |
|---|---|---|
Shampoo
711 products
|
leading · #1 | |
Conditioner
622 products
|
leading · #1 | |
Leave-in
378 products
|
leading · #1 | |
Mask / treatment
319 products
|
leading · #1 | |
Styler: gel
132 products
|
leading · #1 | |
Styler: mousse
121 products
|
leading · #1 | |
Heat protectant
120 products
|
leading · #1 | |
Co-wash
90 products
|
leading · #1 | |
Styler: curl cream
83 products
|
leading · #1 | |
Styler: paste
70 products
|
leading · #1 |
14 more product types
| Product type | How common | Typical position on label ? |
|---|---|---|
Scalp treatment
68 products
|
leading · #1 | |
Styler: hairspray
64 products
|
leading · #3 | |
Styler: volumizer
59 products
|
leading · #1 | |
Styler: smoothing cream
46 products
|
leading · #1 | |
Finisher: oil
45 products
|
secondary · #11 | |
Finisher: serum
42 products
|
leading · #1 | |
Styler: texture spray
39 products
|
leading · #1 | |
Finisher: shine spray
32 products
|
supporting · #5 | |
Finisher: anti frizz finish
12 products
|
leading · #1 | |
Styler: edge control
9 products
|
leading · #1 | |
Styler: refresh spray
9 products
|
leading · #1 | |
Styler: lotion
7 products
|
leading · #1 | |
Finisher: end oil
5 products
|
leading · #1 | |
Dry shampoo
1 product
|
supporting · #7 |
| Product type | Products | Share of category | Median position | Earliest position | Band |
|---|---|---|---|---|---|
| Shampoo | 711 | 86% | 1 | 1 | leading |
| Conditioner | 622 | 89% | 1 | 1 | leading |
| Leave-in | 378 | 90% | 1 | 1 | leading |
| Mask / treatment | 319 | 83% | 1 | 1 | leading |
| Styler: gel | 132 | 85% | 1 | 1 | leading |
| Styler: mousse | 121 | 87% | 1 | 1 | leading |
| Heat protectant | 120 | 83% | 1 | 1 | leading |
| Co-wash | 90 | 92% | 1 | 1 | leading |
| Styler: curl cream | 83 | 79% | 1 | 1 | leading |
| Styler: paste | 70 | 78% | 1 | 1 | leading |
| Scalp treatment | 68 | 43% | 1 | 1 | leading |
| Styler: hairspray | 64 | 67% | 3 | 1 | leading |
| Styler: volumizer | 59 | 89% | 1 | 1 | leading |
| Styler: smoothing cream | 46 | 82% | 1 | 1 | leading |
| Finisher: oil | 45 | 26% | 11 | 1 | secondary |
| Finisher: serum | 42 | 53% | 1 | 1 | leading |
| Styler: texture spray | 39 | 67% | 1 | 1 | leading |
| Finisher: shine spray | 32 | 49% | 5 | 1 | supporting |
| Finisher: anti frizz finish | 12 | 52% | 1 | 1 | leading |
| Styler: edge control | 9 | 56% | 1 | 1 | leading |
| Styler: refresh spray | 9 | 69% | 1 | 1 | leading |
| Styler: lotion | 7 | 58% | 1 | 1 | leading |
| Finisher: end oil | 5 | 56% | 1 | 1 | leading |
| Dry shampoo | 1 | 33% | 7 | 7 | supporting |
No product-type differences have been researched yet — the reading below is computed from where it sits on the labels in our library.
Position footprint
Every listing in our library, by position on the label.
| Positions | Zone | Listings |
|---|---|---|
| 1-3 | Leading | 3358 |
| 4-8 | Supporting | 67 |
| 9-15 | Secondary | 82 |
| 16-25 | Lower | 36 |
| 26+ | Trace | 17 |
How to read this
US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order.
So position tells you about relative amount only above that line, and we never convert a position into a percentage.
Why it matters to shoppers
What this ingredient is evidence of, what it is not evidence of, and what our own method can and cannot tell you.
- a light, fast-drying formula
- a rinse-clean feel
- an exact safety score — we do not publish one, for any ingredient
- how a finished product performs by itself — that is the whole formula, not one line of it
- the exact percentage in a bottle — label position never converts into a number
- a primary solvent near the top of the ingredient list in our shampoos
- it was on the label of every product we counted — we read printed ingredient lists, not marketing copy
- that a product is right or wrong for you
We do not publish safety scores or hazard grades. Where a regulator has published a restriction or a use condition, we state it and cite it; otherwise we describe what the ingredient does and stop.
Commonly paired with
Ingredients that appear alongside this one most often in our library. Near-universal ingredients are excluded — they pair with everything and tell you nothing.
- Benzyl Alcohol · 896
- Behentrimonium Chloride · 870
- Cetrimonium Chloride · 788
- Cetyl Alcohol · 724
- Tocopherol · 722
- Hexyl Cinnamal · 714
- Disodium EDTA · 692
- Caprylyl Glycol · 685
- Sodium Chloride · 670
- Propylene Glycol · 646
The number beside a name is how many products in our library list both.
These ingredients tend to appear together to carry the formula and let it dry, improve feel after rinsing, and soften the strand.
Found in these products
The most prominent placements first. The badge is the position on that product’s own ingredient list.
18.21 Man Made · Styler
Sweet Tobacco Medium Hold, High Shine Hair Styling Pomade
#1 on the label · $13.00/oz
18.21 Man Made · Styler
Sweet Tobacco Medium Hold, No Shine Hair Styling Clay
#1 on the label · $13.00/oz
18.21 Man Made · Styler
Sweet Tobacco Soft Hold, Medium Shine Hair Styling Paste
#1 on the label · $13.00/oz
4U by Tia · Mask / treatment
Deep Conditioning Repair Mask
#1 on the label · $1.25/oz
Act+Acre · Conditioner
1% Vitamin B-5 Fine Hair Conditioner
#1 on the label · $3.20/oz
Act+Acre · Leave-in
2% Squalane Anti-Frizz Leave In Conditioner
#1 on the label
Act+Acre · Scalp treatment
4% Niacinamide Scalp Serum for Oily Scalp + Hair
#1 on the label · $30.91/oz
Act+Acre · Shampoo
Balancing Shampoo
#1 on the label · $2.55/oz
Act+Acre · Shampoo
Clarifying Hard Water Shampoo
#1 on the label · $3.20/oz
Act+Acre · Mask / treatment
Conditioning Hair Mask
#1 on the label · $8.44/oz
Act+Acre · Scalp treatment
Daily Hydro Scalp Serum with Hyaluronic Acid
#1 on the label · $24.00/oz
Act+Acre · Conditioner
Daily Hydro™ Hydrating Conditioner
#1 on the label · $3.80/oz
Identity
What this entry is, and what our references call it.
No public-domain structure depiction is available for this entry.
Water
- --- balancing moisturizer: aqua (water)
- aqua
- aqua (eau/water)
- aqua (oleology program)
- aqua (purified water)
- aqua (purified)
- aqua (water
- aqua (water, eau)
- aqua (water)
- aqua (water) (eau)
- aqua (water)/eau
- aqua (water/ eau)
- aqua (water/eau)
- aqua / water
- aqua / water / eau
- aqua water
- aqua/ water / eau
- aqua/eau
- aqua/eau/water
- aqua/water
- aqua/water/ eau
- aqua/water/eau
- aqua/water/eau (water)
- de-ionized water
- deionized water
- deionized water (aqua)
- distilled water
- distilled water (aqua)
- distilled water botanically infused with horsetail, rosemary & sage
- eau
- eau/water
- eau/water/aqua
- purified water
- purified water (and) salix alba (white willow) bark extract (and) hibiscus sabdariffa (hibiscus) flower extract (and) panax ginseng (ginseng) root extract (and) ilex paraguariensis (yerba mate) leaf extract (and) gluconolactone (and) sodium benzoate
- purified water (aqua, eau)
- purified water (aqua)
- sea water (maris aqua/eau de mer)
- sea water/maris aqua/eau de mer
- step one (protein treatment): water (aqua, eau)
- two-step protein treatment: water (aqua, eau)
- water
- water (aqua
- water (aqua / eau)
- water (aqua eau)
- water (aqua, eau)
- water (aqua,eau)
- water (aqua)
- water (aqua) (eau)
- water (aqua)(eau)
- water (aqua)/eau
- water (aqua/eau)
- water (eau)
- water / aqua / eau
- water, aqua
- water, aqua, eau
- water(aqua/eau)
- water/aqua
- water/aqua/eau
- water/eau
- water/eau (aqua)
- water/eau/aqua
- water\aqua\eau
- water\eau
For your hair?
Whether Water matters for your hair depends on your hair.
the 1st most-listed solvent or propellant in our libraryWhat this ingredient does, and where it sits on the labels we have researched.
A verdict on any product that contains it, and never a safety grade.
We do not physically test your hair. Everything above is read from the ingredient lists in our library and from published references — the consultation is what turns it into a plan.
References
Seed entry — sourcing in progress Written from our reference work; primary sourcing is still being attached.
No published source is attached to this entry yet.
How this page was made
- Every number above is counted from the ingredient lists in our own product library — 3069 of 3889 researched products list this ingredient. Nothing on this page is written per ingredient.
- The dots are named levels read from an ingredient’s chemical class, charge, solubility, or where it sits on the labels we have — never a score.
- US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order. Position tells you about relative amount only above that line, and we never convert a position into a percentage.
- The prominence bands (leading, supporting, secondary) are the same ones the product pages use to read a single label, applied here to the median position across a category.
- We do not publish safety scores or hazard grades. Where a regulator has published a restriction or a use condition, we state it and cite it; otherwise we describe what the ingredient does and stop.
- Identifiers and references appear only when a published source is attached to this entry; where none is, the row is simply absent rather than filled in.
- This is cosmetic information, not medical advice, and nothing here diagnoses or treats a health condition.
- Entry last updated 2026-08-28. Product-page methodology: the product library.