Nioxin System 1 Leave In Treatment — front of package

Nioxin

System 1 Leave In Treatment

Scalp treatment

Scalp treatment
Sulfate-free
Silicone-free
Curly-method
Not cruelty-free · PETA-listed

Size3.38 fl ozmost listed · 2 sizes

Price$27seen at one store · 3.38 oz · from $6.36/oz in the 6.76 oz

Price / oz$10.28/ozat 3.38 oz

Where to buy3 stores · 2 sizes

Scent:

The ingredient list declares fragrance. What it smells of is not stated, and we do not guess.

Manufacturer page: nioxin.com

Personal fit

Is this right for you?

Factor Your profile Fit

Best for hair types All types Not in your profile

Moisture level Moderate Not in your profile

Slip / detangling Little Not in your profile

Weight on hair Light Not in your profile

Fragrance Present Not in your profile

Protein Minor Not in your profile

Silicone / wax buildup None Not in your profile

Clarifying wash needed Moderate Not in your profile

Parabens / preservatives Present Not in your profile

Essential oils Present Not in your profile

Show all 19 factors we check

The rest of what your plan weighs on this product.

Fast-drying alcohol None Not in your profile

Vegan / cruelty-free Not cruelty-free · PETA-listed Not in your profile

Animal-derived ingredients Not yet verified Not in your profile

Heavy humectants Not heavy Not in your profile

Hard-water defence High Not in your profile

UV filter None listed Not in your profile

Ingredient list 43 ingredientsA long list Not in your profile

Price tier Salon Not in your profile

Where to buy it Salons · Specialty beauty +1Widely sold Not in your profile

The consultation builds your hair profile, then reads every factor in this table against it — and tells you where this product fits, or what to use instead.

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Upper-mid price for a scalp treatment

$10.28/oz at 3.38 oz — more than 58% of the 152 scalp treatments , which mostly run $3.22–20.64/oz.

Price and stores

Great for

Fine hairthat flattens under most products

Silicone-free routinesno silicones appear in the list

Very dry hairno fast-drying alcohol in the list

Easy to findsold through several channels

Maybe skip if

this product carries a scent

Vegan and cruelty-freeour record does not support both claims here

Tight budgetsit sits in the upper price tiers

Whether this much richness is right for you depends on your strand thickness, porosity, and how easily your hair flattens — that is what the consultation works out.

What the formula actually does

Read from the label, not the marketing

Each row says where it comes from: F means we derived it from this product’s own ingredient list, S means it is a claim the brand makes that the formula neither confirms nor contradicts.

Slip and detangling Little

Nothing here is built to reduce combing force.

Oils and butters None

No oils or butters in the list.

Weight on the hair Light

Water-first and light: unlikely to flatten fine hair.

Water-binding (humectants) Moderate

Humectants in the working part of the formula.

Protein Minor

Protein appears, low enough to be a supporting ingredient.

Needs detergent to remove No

Nothing here needs a detergent wash to remove.

Hard-water defence Chelators present

Chelators are present — they bind hard-water and pool minerals.

Fragrance Present

Fragrance is listed; it sits below the working ingredients.

from the formula stated by the brand reported by reviewers Scale: 1 dot low · 5 dots high, within this product type.

Ingredients that matter

The ingredients that change a decision

The workhorse ingredients plus anything lower down that changes a decision. These chips name what an ingredient does — they are not safety scores, and no ingredient here is rated good or bad on its own.

Ingredient	What it does	Why it matters	Chip
WaterAqua/Water/Eau	solvent	The base everything else is dissolved in	Neutral
Niacinamide	vitamin	A marketed vitamin addition	Detangles
Caffeine	active	The over-the-counter active	Active
Phenoxyethanol	preservative	Keeps the product from spoiling	Stabilizes
Sodium Benzoate	preservative	Keeps the product from spoiling	Stabilizes
Benzyl Alcohol	preservative	Keeps the product from spoiling	Stabilizes
Acrylates/C10-30 Alkyl Acrylate Crosspolymer	thickener	Adjusts the texture	Holds
Polysorbate 80	emulsifier	Stabilises the mix	Stabilizes
FragranceParfum/Fragrance	fragrance	The scent	Fragrance
Mentha Arvensis Leaf Oil	fragrance	The scent	Fragrance
Mentha Piperita (Peppermint) Oil	botanical extract	A trace plant extract	Fragrance
Limonene	fragrance	The scent	Fragrance

What the list leaves out, and what it carriesThe list carries no sulfates, silicones, or drying alcohols. Fragrance is on the label. Hard-water chelators are present.

Full ingredient list (43)

US labelling rules put ingredients above 1% in descending order of amount; below 1% they may be listed in any order. Annotations keep three readings separate: the ingredient's general function, its role in this product type, and what its position can support.

1 Water · Aqua/Water/Eau

General function
The base of almost every rinse-off and cream hair product. It carries everything else and is normally the first ingredient on the label.

Leading ingredient
Listed in the first three ingredients, it is likely a structural part of this formula.
- solvent
2 Niacinamide

General function
Vitamin B3, used in scalp products for conditioning claims.

Leading ingredient
Listed in the first three ingredients, it is likely a structural part of this formula.

May suitFrizz-prone, damaged, or high-friction hair
Deposits a lubricating layer that makes combing easier, which is most of what stops mechanical damage adding to frizz.

PubChem
- vitamin
- conditioning agent
3 Caffeine

General function
Included in scalp and thickening products for label appeal. Evidence for applied caffeine changing hair growth is limited.

Leading ingredient
Listed in the first three ingredients, it is likely a structural part of this formula.
PubChem
- active
▾Below about this point, order stops being meaningful — these are typically used at 1% or less.
4 Phenoxyethanol

General function
The most common modern preservative; it keeps the product free of bacteria and mould. It sits well below 1% of the formula.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.
PubChem
- preservative
5 Sodium Benzoate

General function
A food-grade preservative that works only in acidic formulas, which is why it usually appears alongside citric acid.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.
PubChem
- preservative
6 Benzyl Alcohol

General function
A preservative and solvent that also occurs naturally in some essential oils.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.
PubChem
- preservative
- solvent
7 Acrylates/C10-30 Alkyl Acrylate Crosspolymer

General function
A gel-forming thickener that also keeps oils suspended. It contributes a little hold.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitClimate-sensitive or frizz-prone hair
A set polymer film is a physical barrier to humidity, so a style keeps its shape longer in damp conditions.

May suitMaximum-hold styling
Synthetic film formers dry into a continuous film, which is what holds a shape against movement and against humid air.

DependsBuild-up-sensitive routines
Some acrylate copolymers rinse with water and some need a detergent; the label alone does not say which one a formula used.
- thickener
- polymer
- film former
8 Polysorbate 80

General function
A solubiliser that dissolves fragrance and oils into water so the product stays clear.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.
- emulsifier
- solubilizer
9 Polysorbate 60
- emulsifier
- solubilizer
10 Acetamide MEA

General function
A humectant that also improves slip, used in conditioners and styling creams.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitFrizz-prone, damaged, or high-friction hair
Deposits a lubricating layer that makes combing easier, which is most of what stops mechanical damage adding to frizz.

May suitVery dry or highly damaged hair
Humectants bind water into the strand, and water — not oil — is what makes dry hair flexible instead of brittle.

DependsClimate-sensitive or frizz-prone hair
A humectant follows the air: it holds water in humid conditions and can give it up in very dry ones. Climate decides what it does more than the label does.

PubChem
- humectant
- conditioning agent
11 Triethanolamine

General function
A base used in trace amounts to neutralise acidic polymers so a gel thickens.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

DependsFrizz-prone, damaged, or high-friction hair
pH adjusters are how a formula is brought to a chosen acidity, and an acidic formula keeps the cuticle lying flatter than an alkaline one. Which way this one moves the pH depends on the formula, and the finished pH is not on the label.

PubChem
- pH adjuster
12 PEG-23M
- polymer
- thickener
- binder
13 Propylene Glycol

General function
A small humectant and solvent that keeps formulas stable and helps active ingredients spread.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitFine or easily flattened hair
Light and water-binding rather than oily, so it hydrates without contributing weight.

May suitVery dry or highly damaged hair
A small water-binding solvent. It holds moisture and helps the rest of the formula spread evenly over the strand.

DependsClimate-sensitive or frizz-prone hair
A humectant follows the air: it holds water in humid conditions and can give it up in very dry ones. Climate decides what it does more than the label does.

PubChem
- humectant
- solvent
14 Tetrasodium EDTA

General function
Binds the metal ions in hard water so they cannot dull hair or destabilise the formula.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitBuild-up-sensitive routines
Binds the calcium and magnesium in hard water, which is what stops mineral deposits accumulating on the strand wash after wash.

May suitGray, silver, or brass-prone hair
Copper and iron carried in tap water deposit on the strand and read as a dull, warm cast on gray or light hair. A chelator holds those metals in solution so the wash carries them off.

PubChem
- hard-water chelator
15 Methyl Nicotinate
16 Fragrance · Parfum/Fragrance

General function
An undisclosed blend of scent ingredients. Regulations let it stay unlisted, so a fragrance-free product is the only way to be certain what is not in it.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May not suitFragrance-sensitive routines
Declared fragrance. On a fragrance-sensitive routine this is the line that decides it, wherever it sits on the label.
- fragrance
- declared fragrance
17 Mentha Arvensis Leaf Oil

General function
Cornmint oil, used for a cooling sensation and mint scent.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May not suitFragrance-sensitive routines
Declared fragrance. On a fragrance-sensitive routine this is the line that decides it, wherever it sits on the label.
- fragrance
- botanical extract
18 Mentha Piperita (Peppermint) Oil

General function
Peppermint essential oil, used for scent and the cooling feeling on the scalp.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May not suitFragrance-sensitive routines
Essential oils are fragrance. Several carry constituents on the EU list of declared fragrance allergens, so a label with no fragrance line can still be a scented product.
- botanical extract
- essential oil
- fragrance
19 PEG-30 Dipolyhydroxystearate
20 Trideceth-6
- emulsifier
- solubilizer
21 Limonene

General function
A citrus-smelling fragrance component that EU rules require to be named separately because some people react to it.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May not suitFragrance-sensitive routines
One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

PubChem
- fragrance
- named fragrance allergen
22 Camellia Sinensis (Green Tea) Leaf Extract · Camellia Sinensis Leaf Extract
- botanical extract
- antioxidant
23 Silica

General function
A fine mineral powder that absorbs oil and adds grip. It is what makes texture powders and matte pastes feel dry to the touch.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitFine or easily flattened hair
A dry powder takes up oil and adds friction between strands, which is most of what root lift in fine hair actually is.

PubChem
- powder
- thickener
- mineral
24 Cystine Bis-PG-Propyl Silanetriol

General function
A cystine derivative modified to bind more firmly to the strand, used in strengthening formulas.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitVery dry or highly damaged hair
Amino acids are the smallest protein fraction and bind water as well, so they add far less stiffness than a hydrolysed protein does.

DependsProtein-sensitive hair
The lightest option in the protein family, but still protein — worth watching if protein reliably stiffens your hair.
- amino acid
- protein
25 Biotin
- vitamin
26 Lecithin

General function
A soy- or sunflower-derived lipid that helps conditioning ingredients spread evenly on the strand.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitFrizz-prone, damaged, or high-friction hair
Emollients fill and smooth the surface of the strand, which lowers the friction that lifts the cuticle and reads as roughness.

PubChem
- emulsifier
- emollient
27 Tocopheryl Acetate
- antioxidant
- vitamin
28 Humulus Lupulus (Hops) Flower Extract
- botanical extract
29 Citrus Paradisi (Grapefruit) Peel Extract
- botanical extract
30 Urtica Dioica (Nettle) Leaf Extract
- botanical extract
31 Acer Saccharum (Sugar Maple) Extract
- botanical extract
32 Citrus Limon (Lemon) Peel Extract
- botanical extract
33 Saccharum Officinarum/Sugar Cane Extract/Extrait de canne à sucre
34 Vaccinium Myrtillus Leaf Extract
- botanical extract
35 Faex Extract/Yeast Extract/Extrait de levure
36 Propylparaben
- paraben
- preservative
37 Citrus Aurantium Dulcis (Orange) Fruit Extract
- botanical extract
38 BHT
- antioxidant
39 Potassium Sorbate
- preservative
40 Maltodextrin

General function
A starch fragment that soaks up oil and water, which is what puts it in dry shampoos. It also carries spray-dried plant extracts and leaves a light film.

Estimated lower-concentration zone
It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

May suitFine or easily flattened hair
Takes up oil at the root, which is where fine hair goes flat first.

May suitMaximum-hold styling
Film formers are what hold a style: they dry into a connected film across the strands so the shape resists movement.

DependsCurls or waves needing flexible hold
How rigid the finish is depends on which polymer it is and what the formula pairs with it, not on there being one.
- absorbent
- film former
- binder
41 Methylparaben
- paraben
- preservative
42 Ethylparaben
- paraben
- preservative
43 Butylparaben
- paraben
- preservative

What the whole list adds up to

10 botanical extracts
8 preservatives
4 emulsifiers
4 fragrances
4 parabens
3 solvents
3 vitamins
3 thickeners
3 solubilizers
3 antioxidants
2 conditioning agents
2 polymers
2 film formers
2 humectants

Ingredient list captured 2026-09-11. Formulas change — check the package in your hand when an ingredient matters to you.

Price · 3.38 oz

Seen at $27 lowest of 2 stores · checked Sep 13

Good value under $37 Under $10.96/oz it costs less than three-quarters of the 8 products we score as doing the same job

Good value on sale. Some stores sell it under the $37 line; products that do this job typically go for about $69 at this size.

Sizes

3.38 ozmost listed

$27

$10.28/oz

6.76 oz

$43

$6.36/oz

The 6.76 oz costs 38% less per ounce than the 3.38 oz.

Show the price ladder

Price for 3.38 ozlower is better

Where we’ve seen it4 listings · 3 stores

3.38 ozmost listed

Amazon
$27.00

3.38 oz · $7.99/oz

Sep 13Lowest per oz
Ulta Beauty
$27.00

3.3 oz · $8.18/oz

Sep 11
LookFantastic
$42.50

3.38 oz · $12.57/oz

Sep 11

6.76 ozBest per ounce

Amazon
$43.00

6.76 oz · $6.36/oz

Sep 13Lowest per oz

Sorted by price per ounce. Dated observations from our research, not live prices. Direct store pages, no affiliate links. We don’t sell this product.

How we work this out

3.38 oz is the size stores list most often; every comparison on this page is made at it. Other sizes are shown in the Sizes row and the store list.
Seen at $27 is the price we have observed for the 3.38 oz. We need three stores before we call a price commonly seen.
Good value under $37 comes from the 8 products we score as doing the same job as this one. A quarter of them cost less than $10.96/oz; at 3.38 oz that is $37. Under that line you are paying less than most of them.
Each size is guarded on its own, so a multipack or a marketplace listing at one size cannot move another.
About $69 is what those same products typically cost at this size — the midpoint of their prices per ounce, scaled to 3.38 oz.

Formula

Formula score

3 of 10

Mid-range per ounce for a shorter formula: there is no conditioning agents up front here.

How the score is counted

1 products that do the same job cost less per ounce
Costs more per ounce than 58% of the 152 scalp treatments we’ve priced
No conditioning agents up front in the formula
No oils or butters in the working zone either

Conditioning agents up frontWhat makes wet hair comb through.3 pts
Oils or butters in the working zoneSoftens the strand rather than just coating it.2 pts
Slip for detanglingReduces the force it takes to comb wet hair.2 pts
A humectantBinds water into the hair.1 pt
A pH adjusterBrings the formula to the acidic pH hair prefers.1 pt
Fragrance kept out of the top eightScent as a finishing touch, not a major share.1 pt

The formula score is completeness for the job: the share of the systems this product type is normally built around that we can find in this list, weighted. It is not efficacy, not quality, and it never compares across product types.

Does the same job, for less

Same derived functions — what it cleans, conditions, coats or holds — at a lower cost per ounce. Scent, texture and where you buy it can still differ.

NioxinLowest cost per oz System 3 Leave In Treatment $6.36/oz $3.92/oz less

Lightweight
Silicone-free
Alcohol-free

· Same function

Differs: 6.7 oz bottle

Compare

See more alternatives in the product library

These are functional neighbours, not personal recommendations — they are close on formula, not chosen for anyone. Get the one that fits your hair, routine, and budget

Final decision

Should you buy it?

Good for the right person

Best user

Fine or easily-flattened hair who want something that will not weigh hair down and a silicone-free formula

Biggest tradeoff

Less suited to anyone sensitive to fragrance, vegan and cruelty-free shopping, or people shopping on a budget

Best alternative if not

Consider Nioxin System 3 Leave In Treatment, for similar results at a lower price

We do not sell products or take placement fees. This page states what the formula and the prices show; the consultation is what matches it to a person.

Claims check

What the brand says, against what the formula shows

Claims are quoted from the brand. We only mark one supported, partly supported, or conflicting when the ingredient list actually speaks to it; everything else stays "stated by the brand", which is not a criticism — most claims simply cannot be read off a label.

SupportedBacked by ingredients

Partly supportedSome supporting logic

Stated by brandNo clear evidence

Potential conflictFormula works against claim

Thickens the hair

It reads light on the strand, which is what volume claims depend on.

Acrylates/C10-30 Alkyl Acrylate Crosspolymer
PEG-23M

Supported

Leaves room for lift.

Nourishes the scalp

Humectants and emollients are present, but lower in the list than the claim implies.

Acetamide MEA
Propylene Glycol

Partly supported

Some hydration, at a low level.

How to read this

We look at the first 10–15 ingredients and what they do in a formula — not marketing. If the list doesn't speak to a claim, we don't assume.

How this page was made

Everything above is generated from our researched product record — identity, the ingredient list as printed, the brand's own claims, dated price observations, and review themes written in our researchers' own words. No part of this page is written per product.
The value band is a fixed label over two stored numbers: this product’s cost per ounce as a percentile of every product of this type we have priced, each at the size it is most often sold in, and how many products we score as doing the same job cost at least a quarter less per ounce.
Both scores out of ten are defined on this page. The formula score is completeness for the job, computed from a fixed per-format checklist shown beneath the gauge; the price score is cost per ounce against every product of this type we have priced.
The "Is this right for you?" panel reads only your own consultation answers, and it applies exactly the filters our recommendation engine applies. It is computed when you load the page and is never stored on it.
6 sources consulted for this product (2 manufacturer or regulatory, 1 retailer, 3 editorial), last checked 2026-09-13.
Ingredient references are linked for 8 of 14 product-aware annotations on this page. Fit notes are conditional formulation guidance, not a conclusion about the finished product or about you.
We have not tested this product in a lab and we do not physically test your hair. Formula readings come from the ingredient list; behaviour claims are labelled as the brand's.
Ingredient order tells you relative amount only above roughly 1%. Prices are observations on the dates shown and change without notice.
Ingredient names link to our ingredient library, where each entry shows what it does, which product types use it, and where it usually sits on a label across everything we have researched.
This is cosmetic information, not medical advice, and nothing here diagnoses or treats a health condition.
Formula readings: derivation v22. Record last updated 2026-09-11.