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Side by side

Act+Acre 4% Niacinamide Scalp Serum for Oily Scalp + Hair vs Act+Acre Stem Cell Scalp Serum

92% function match · 6 of the 7 functions we compared match Formula overlap 34%. Act+Acre 4% Niacinamide Scalp Serum for Oily Scalp + Hair and Act+Acre Stem Cell Scalp Serum share 2 ingredients among each other's most prominent.

Based on your consultation

Which of these fits your hair?

We check your pattern, moisture need, scalp, fragrance tolerance, weight sensitivity and more against each formula — and say which one lines up.

Your profile at a glance

  • Your answers appear here
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When each one is the right call

What each formula is built for, from its own ingredient list.

Side by side

Every trait, aligned

One row per trait, read from each product’s own ingredient list and record. A dash means we have not researched that field for that product — it is not a “no”.

Trait
Act+Acre 4% Niacinamide Scalp Serum for Oily Scalp + Hair — 2.2 oz container Act+Acre

4% Niacinamide Scalp Serum for Oily Scalp + Hair

  • Scalp treatment
  • Prestige
Act+Acre Stem Cell Scalp Serum — 2.2 oz container Act+Acre

Stem Cell Scalp Serum

  • Scalp treatment
  • Prestige
Price, size & price per ounce
about $68 2.2 oz · $30.91/oz
$86 2.2 oz · $39.09/oz
Value / price positioning
Same job for less elsewhere $$$$$ Prestige tier · costs more than 92% of the 154 scalp treatments we’ve priced
Same job for less elsewhere $$$$$ Prestige tier · costs more than 95% of the 154 scalp treatments we’ve priced
Best for hair types
All types Nothing in the formula or the claims narrows this to one pattern. Your hair
All types Nothing in the formula or the claims narrows this to one pattern. Your hair
Moisture level Same
High Humectants near the top — water-binding is a headline mechanism here. Your hair
High Humectants near the top — water-binding is a headline mechanism here. Your hair
Slip / detangling Same
Little Nothing here is built to reduce combing force. Your hair
Little Nothing here is built to reduce combing force. Your hair
Silicone / wax buildup Same
None Nothing here needs a detergent wash to remove. Your hair
None Nothing here needs a detergent wash to remove. Your hair
Clarifying wash needed
Low Your hair
Low Your hair
Oils and butters Same
None No oils or butters in the list. Your hair
None No oils or butters in the list. Your hair
Hard-water defence Same
Chelators present Chelators are present — they bind hard-water and pool minerals. Your hair
Chelators present Chelators are present — they bind hard-water and pool minerals. Your hair
Formula completeness
out of 10
A simple formula
out of 10
A simple formula
Who should choose this
—
—
Why you might skip it
  • 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
  • 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
from the formula stated by the brand reported by reviewers Scale: 1 dot low · 5 dots high, within this product type.
More facts about each one
Type
Scalp treatmentserum
Scalp treatmentserum
Where to buy
Brand website
Brand website
Vegan
—
Vegan · label states

Facts as we recorded them. A dash means we have not researched that field for that product — it is not a "no".

The bottom line

The bottom line depends on your hair

Which of these two suits you is a question about your hair, not about them. The consultation answers it — and tells you what your routine needs around it.

Take the consultation

$49.00 once, for your consultation and hair profile. No subscription, no required purchases.

The detail behind the table

Where the readings above come from: the ingredient lists themselves, each brand’s claims checked against them, what owners report, and cost per ounce in context.

Shared and distinct ingredients

Shared and distinct ingredients

Computed from the ingredient lists as printed. "Shared" means both lists carry it; where it sits on each label is stated, because position is what tells you how much.

What both formulas carry

Ingredient4% Niacinamide Scalp Serum for Oily Scalp + HairStem Cell Scalp Serum
Water
Neutral
#1Leading
#1Leading
Pentylene Glycol
Moisturizes
#2Leading
#16Below the 1% line
Propanediol
Moisturizes
#3Leading
#19Below the 1% line
Glycerin
Moisturizes
#5Supporting
#2Leading
Citric Acid
pH balancer
#16Below the 1% line
#8Below the 1% line

What only one of them carries

4% Niacinamide Scalp Serum for Oily Scalp + Hair

Stem Cell Scalp Serum

Full ingredient list — 4% Niacinamide Scalp Serum for Oily Scalp + Hair (19)
Full ingredient list — Stem Cell Scalp Serum (24)

Claims check

What each brand says, against what each formula shows

Claims are quoted from each brand. We only mark one supported, partly supported, or conflicting when that product’s ingredient list actually speaks to it.

Verdicts4% Niacinamide Scalp Serum for Oily Scalp + HairStem Cell Scalp Serum
Supported
0
0
Partly supported
0
0
Stated by brand
4
5
Potential conflict
0
0

4% Niacinamide Scalp Serum for Oily Scalp + Hair

  • Control excess oil + odorStated by brandCan’t be confirmed from label.
  • Balances scalp pH to stop oil production before it beginsStated by brandCan’t be confirmed from label.
  • Extends time between washesStated by brandCan’t be confirmed from label.
  • Stabilizes the scalp to be less oily over timeStated by brandCan’t be confirmed from label.

Stem Cell Scalp Serum

  • 56% less visible hair fall-out in 12 weeksStated by brandOnly the brand’s testing shows this.
  • 86% noticed more hair coverage on the scalp. 85% noticed more volumeStated by brandOnly the brand’s testing shows this.
  • 90% saw new hair growth in 6 weeksStated by brandOnly the brand’s testing shows this.
  • 100% agree product increased hair thicknessStated by brandOnly the brand’s testing shows this.
  • 100% agree hair felt stronger + healthierStated by brandOnly the brand’s testing shows this.

What owners say

What people report

Recurring themes our researchers wrote in their own words from sourced reviews. We do not store or scrape star ratings, and we never balance one product’s themes against another’s by inventing them.

Both praised for a light feel.

4% Niacinamide Scalp Serum for Oily Scalp + Hair

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

Stem Cell Scalp Serum

Some reviewers say their overall hair shedding and daily hair loss dropped noticeably after starting the serum

reviewers tracking shedding/hair loss

Reviewers also credit it with a healthier scalp overall — less itching, dryness and tightness — alongside the hair-growth effect

reviewers describing scalp feel, not just hair growth

Reviewers repeatedly note the texture is lightweight and does not leave hair greasy, including right at the hairline

reviewers commenting on daily application

Multiple reviewers report visible new hair growth and thicker-looking hair after a few months of consistent use

reviewers using the serum for 3+ months

Price check

Cost per ounce, in context

Cost per ounce against every product of this type we have priced, each at the size it is most often sold in. Value labels are computed from that percentile and from how many products that do the same job cost less; they are comparisons, not judgements about a brand.

$30.91/oz vs $39.09/oz — Act+Acre Stem Cell Scalp Serum costs about 1.3× more per ounce than Act+Acre 4% Niacinamide Scalp Serum for Oily Scalp + Hair.

$1.25/oz median $7.19/oz $55.03/oz $30.91/oz 4% Niacinamide Scalp Serum $39.09/oz Stem Cell Scalp Serum

Every mark sits on one distribution because these are compared against the same set: 154 scalp treatments with a computable unit price.

Value read4% Niacinamide Scalp Serum for Oily Scalp + HairStem Cell Scalp Serum
Label
Same job for less elsewhereYou are paying above the range for a formula close to several lower-priced options.
Same job for less elsewhereYou are paying above the range for a formula close to several lower-priced options.

Computed from cost per ounce against every product of this type we have priced, and from how many products that do the same job cost less. It is a comparison, not a judgement about the brand.

Compare with something else

Close formulas to each of these, as their own comparison pages.

4% Niacinamide Scalp Serum for Oily Scalp + Hair vs Daily Hydro Scalp Serum with Hyaluronic AcidAct+Acre · 99% function matchStem Cell Scalp Serum vs Hair Density Serum IntenseGrow Gorgeous · 99% function match4% Niacinamide Scalp Serum for Oily Scalp + Hair vs Scalp SerumDivi · 99% function matchStem Cell Scalp Serum vs Youth Juice Collagen Scalp SerumColor Wow · 96% function match4% Niacinamide Scalp Serum for Oily Scalp + Hair vs The Treatment Scalp SerumKilgourMD · 99% function matchStem Cell Scalp Serum vs Lock Drops Anti-Shedding Scalp & Hair SerumBondi Boost · 96% function match4% Niacinamide Scalp Serum for Oily Scalp + Hair vs Restoring Hair & Edge Drops XLCÉCRED · 99% function matchStem Cell Scalp Serum vs Revive+ Densifying Serum for WomenBosley · 96% function match

4% Niacinamide Scalp Serum for Oily Scalp + Hair · Stem Cell Scalp Serum · All scalp treatments in the library

How this page was made

  • This page is assembled from the same researched records the individual product pages render: identity, each ingredient list as printed, each brand's own claims, dated price observations, and review themes written in our researchers' own words. Nothing on it is written per comparison.
  • We do not rank these against each other. Which of them suits you depends on your hair, and that is what the consultation works out.
  • The formula similarity percentage is a stored, precomputed number: position-weighted overlap of the two ingredient lists blended with agreement on the attributes we derive. It measures how alike two formulas are, not how well either works.
  • 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.
  • 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 were consulted across the products on this page.
  • Ingredient order tells you relative amount only above roughly 1%. Prices are observations on the dates shown and change without notice. We do not sell these products and take no placement fees.
  • This is cosmetic information, not medical advice, and nothing here diagnoses or treats a health condition.

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