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Act+Acre

4% Niacinamide Scalp Serum for Oily Scalp + Hair

Scalp treatment

  • Scalp treatment
  • serum
Size2.2 fl oz
Priceabout $68commonly seen · 2.2 oz
Price / oz$30.91/ozat 2.2 oz

Manufacturer page: actandacre.com

Personal fit

Is this right for you?

Complete the consultation to see exactly how well this product fits your hair and your goals. With 2,400+ products in our library we can match exactly the right products to you.

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  • Your goals, scalp, damage history, water, budget, and scent preferences all shape your plan.

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Same job for less elsewhere

$30.91/oz at 2.2 oz — more than 91% of the 152 scalp treatments , which mostly run $3.22–20.64/oz.

View alternatives

Great for

Nothing in the formula stands out either way.

Maybe skip if

Dry or very humid airwhere heavy humectants work against you
Tight budgetsit sits in the upper price tiers
Picking it up locallywe have it recorded in one channel only

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.

Water-binding (humectants) High

Humectants near the top — water-binding is a headline mechanism here.

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.

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.

IngredientWhat it doesWhy it mattersChip
WaterAqua/Water/Eau solvent The base everything else is dissolved in Neutral
Pentylene Glycol humectant Pulls water into the hair Moisturizes
Propanediol humectant Pulls water into the hair Moisturizes
Niacinamide vitamin A marketed vitamin addition Detangles
Glycerin humectant Pulls water into the hair Moisturizes
Camellia Sinensis (Green Tea) Leaf ExtractCamellia Sinensis Leaf Extract botanical extract A trace plant extract Stabilizes
Lactitol Neutral
Xylitol humectant Adds a little water-binding Moisturizes
What the list leaves out, and what it carriesHard-water chelators are present.
Full ingredient list (19)

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 Pentylene Glycol
    General function

    A humectant that also helps preserve the formula, often used where a brand wants a short preservative list.

    Leading ingredient

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

    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
    • preservative
  • 3 Propanediol
    General function

    A corn-derived humectant and solvent, often chosen as a lighter-feeling alternative to propylene glycol.

    Leading ingredient

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

    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
  • 4 Niacinamide
    General function

    Vitamin B3, used in scalp products for conditioning claims.

    Supporting ingredient

    Listed in positions 4–8, it likely makes a meaningful contribution alongside the formula's main ingredients.

    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
  • 5 Glycerin
    General function

    A small water-loving molecule that draws moisture into the hair and holds it there. It is the most common softening ingredient in conditioners and leave-ins.

    Supporting ingredient

    Listed in positions 4–8, it likely makes a meaningful contribution alongside the formula's main ingredients.

    May suitDry, coarse, or high-porosity hair

    High-porosity hair loses water fast; a humectant holds some of it in place for longer than the wash itself would.

    May suitVery dry or highly damaged hair

    Binds water into the outer layers of the strand, and water is what makes dry hair flexible again rather than brittle.

    DependsClimate-sensitive or frizz-prone hair

    Water moves both ways. Measured across concentrations, glycerin solutions give water up in some conditions and take it from the air in others. What it does for you depends on how much of it is there and on the air around it.

    Scientific Reports
    • humectant
  • Below about this point, order stops being meaningful — these are typically used at 1% or less.
  • 6 Camellia Sinensis (Green Tea) Leaf Extract · Camellia Sinensis Leaf Extract
    General function

    Green tea extract, included for antioxidants and as a marketing-forward botanical.

    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.

    • botanical extract
    • antioxidant
  • 7 Lactitol
  • 8 Xylitol
    General function

    A sugar alcohol that binds water and gives a light, non-sticky moisturised feel.

    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 suitDry, coarse, or high-porosity hair

    High-porosity hair loses water fast; a humectant holds some of it in place for longer than the wash itself would.

    May suitVery dry or highly damaged hair

    Binds water into the outer layers of the strand, and water is what makes dry hair flexible again rather than brittle.

    DependsClimate-sensitive or frizz-prone hair

    A humectant moves water in whichever direction the air allows: it holds moisture in humid conditions and can pull it back out of hair in very dry ones.

    PubChem
    • humectant
  • 9 Sodium Gluconate
    General function

    A gentle, biodegradable chelator that binds hard-water minerals in place of EDTA.

    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
  • 10 Sodium Hyaluronate
    General function

    A large water-binding molecule that sits on the surface holding moisture.

    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 suitDry, coarse, or high-porosity hair

    High-porosity hair loses water fast; a humectant holds some of it in place for longer than the wash itself would.

    May suitVery dry or highly damaged hair

    Binds water into the outer layers of the strand, and water is what makes dry hair flexible again rather than brittle.

    DependsClimate-sensitive or frizz-prone hair

    A humectant moves water in whichever direction the air allows: it holds moisture in humid conditions and can pull it back out of hair in very dry ones.

    • humectant
  • 11 Lactic Acid
    General function

    An acid used to set pH and, in scalp products, to loosen flakes.

    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 suitDry, coarse, or high-porosity hair

    High-porosity hair loses water fast; a humectant holds some of it in place for longer than the wash itself would.

    May suitVery dry or highly damaged hair

    Binds water into the outer layers of the strand, and water is what makes dry hair flexible again rather than brittle.

    DependsClimate-sensitive or frizz-prone hair

    A humectant moves water in whichever direction the air allows: it holds moisture in humid conditions and can pull it back out of hair in very dry ones.

    PubChem
    • pH adjuster
    • humectant
    • exfoliant
  • 12 Caprylhydroxamic Acid
    General function

    A coconut-derived preservative booster that also binds trace metals.

    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
    • preservative
    • hard-water chelator
  • 13 Saccharomyces Ferment Lysate Filtrate
  • 14 Sodium Anisate
  • 15 Sodium Hyaluronate · Hyaluronic Acid
    General function

    A large water-binding molecule that sits on the surface holding moisture.

    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 suitDry, coarse, or high-porosity hair

    High-porosity hair loses water fast; a humectant holds some of it in place for longer than the wash itself would.

    May suitVery dry or highly damaged hair

    Binds water into the outer layers of the strand, and water is what makes dry hair flexible again rather than brittle.

    DependsClimate-sensitive or frizz-prone hair

    A humectant moves water in whichever direction the air allows: it holds moisture in humid conditions and can pull it back out of hair in very dry ones.

    • humectant
  • 16 Citric Acid
    General function

    Used to bring the product to a slightly acidic pH, which helps the cuticle lie flat. It is almost always near the end of the list.

    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

    Holds hard-water minerals in solution so they rinse away instead of depositing on the hair.

    May suitFrizz-prone, damaged, or high-friction hair

    The acid side of pH adjustment, and the reason it matters is measured: alkaline formulas raise the fibre's surface negative charge, increase friction between strands and lift the scales, while lower-pH ones do the reverse.

    May suitGray, silver, or brass-prone hair

    Where a warm cast comes from water minerals rather than from the hair itself, holding those metals in solution is what removes it.

    International Journal of Trichology
    • pH adjuster
    • hard-water chelator
  • 17 Astragalus Membranaceus Root Extract
  • 18 Sodium Benzoate
    • preservative
  • 19 Potassium Sorbate
    • preservative

What the whole list adds up to

  • 7 humectants
  • 4 preservatives
  • 3 solvents
  • 3 hard-water chelators
  • 2 pH adjusters
  • 1 vitamin
  • 1 conditioning agent
  • 1 botanical extract
  • 1 antioxidant
  • 1 exfoliant

Drug facts actives

  • undefined

This product is an over-the-counter drug as well as a cosmetic. It treats a cosmetic scalp condition; it does not diagnose or treat disease.

Ingredient list captured 2026-09-05. Formulas change — check the package in your hand when an ingredient matters to you.

Price · 2.2 oz

Commonly seen about $68 Midpoint $68 · 4 stores · checked Sep 5
Good value under $31 Under $14.19/oz it costs less than three-quarters of the 7 products we score as doing the same job

Priced above the products that do the same job. Stores sell it above the $31 line; products that do this job typically go for about $60 at this size.

Show the price ladder
Where we’ve seen it5 listings · 5 stores

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
  1. 2.2 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.
  2. Commonly seen is the middle half of current prices for the 2.2 oz at recognised stores — the cheapest quarter and the dearest quarter are left out, so one sale or one overpriced listing can’t move it.
  3. Good value under $31 comes from the 7 products we score as doing the same job as this one. A quarter of them cost less than $14.19/oz; at 2.2 oz that is $31. Under that line you are paying less than most of them.
  4. About $60 is what those same products typically cost at this size — the midpoint of their prices per ounce, scaled to 2.2 oz.

Formula

Formula score
3 of 10

Above the range for scalp treatments per ounce for a shorter formula — there is no conditioning agents up front — with 2 close matches costing less.

How the score is counted
  • 2 products that do the same job cost less per ounce
  • Costs more per ounce than 91% 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.

BiolageLowest cost per oz Scalp Sync Purifying & Exfoliating Concentrate $4.13/oz $26.78/oz less
  • Vegan & CF
· Close function
Differs
  • Cruelty-free
  • Vegan
  • Salon tier
Compare
Bread Beauty SupplyClose function Scalp-Serum: Cooling Greens Exfoliating Scalp Treatment $4.38/oz $26.53/oz less
Differs
  • Mint scent
  • Salon tier
  • 1.7 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

Suits every hair pattern

Final decision

Should you buy it?

Hard to justify at this price
Best user

Nothing in the formula narrows this to one kind of hair.

Biggest tradeoff

Worth skipping for very dry or very humid climates, people shopping on a budget, or anyone who wants to pick it up locally

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.

0
SupportedBacked by ingredients
0
Partly supportedSome supporting logic
4
Stated by brandNo clear evidence
0
Potential conflictFormula works against claim
Control excess oil + odor

Odour control is a performance claim we cannot read from the list.

Stated by brand

Can’t be confirmed from label.

Balances scalp pH to stop oil production before it begins

This is a marketing claim; an ingredient list cannot speak to it.

Stated by brand

Can’t be confirmed from label.

Extends time between washes

This is a marketing claim; an ingredient list cannot speak to it.

Stated by brand

Can’t be confirmed from label.

Stabilizes the scalp to be less oily over time

This is a marketing claim; an ingredient list cannot speak to it.

Stated by brand

Can’t be confirmed from label.

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.

Reviewers

What people report

Recurring themes our researchers wrote in their own words from sourced reviews. We do not store or scrape star ratings.

Reviewers describe the texture as lightweight and fast-absorbing, not leaving hair weighed down or greasy despite treating an oily scalp

reviewers commenting on how the serum feels in the hair after application

Many reviewers say the serum lets them go noticeably longer between washes by cutting down scalp oil

reviewers with oily scalps tracking their wash frequency

Several reviewers report their scalp and hair feel generally healthier and stronger with continued use, beyond just oil control

reviewers using the serum for a few weeks or longer

More from Act+Acre

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.
  • 3 sources consulted for this product (1 manufacturer or regulatory, 0 retailer, 2 editorial), last checked 2026-09-05.
  • Ingredient references are linked for 9 of 11 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 2026-09-05.