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Side by side

OGX ProGrowth + Peptide Hair Strengthening Scalp Serum vs Ouidad Curl Therapy Daily Revitalizing Scalp Serum

85% function match · 8 of the 10 functions we compared match Formula overlap 18%. OGX ProGrowth + Peptide Hair Strengthening Scalp Serum and Ouidad Curl Therapy Daily Revitalizing 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
  • Your answers appear here
  • Your answers appear here
  • Your answers appear here

When each one is the right call

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

  • ProGrowth + Peptide Hair Strengthening Scalp Serum — fragrance-free
  • Curl Therapy Daily Revitalizing Scalp Serum — fragrance-free

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
OGX ProGrowth + Peptide Hair Strengthening Scalp Serum — 0.33 oz container OGX

ProGrowth + Peptide Hair Strengthening Scalp Serum

  • Scalp treatment
  • Drugstore
  • Sulfate-free
  • Silicone-free
Ouidad Curl Therapy Daily Revitalizing Scalp Serum — container, alternate view Ouidad

Curl Therapy Daily Revitalizing Scalp Serum

  • Scalp treatment
  • Salon
  • Sulfate-free
  • Silicone-free
Price, size & price per ounce
$10.99 0.33 oz · $34.82/oz
about $44 2 oz · $22.00/oz

Compared at different sizes — 2 oz against 0.33 oz. Per-ounce prices favour the larger bottle.

Value / price positioning
Same job for less elsewhere $$$$$ Drugstore tier · costs more than 93% of the 154 scalp treatments we’ve priced
Same job for less elsewhere $$$$$ Salon tier · costs more than 78% of the 154 scalp treatments we’ve priced
Best for hair types
Wavy–Coily The brand’s own claims name curly or textured hair. 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 Differs
Little Nothing here is built to reduce combing force. Your hair
Moderate Conditioning agents are present, lower in the list. Your hair
Weight on hair Same
Light Water-first and light: unlikely to flatten fine hair. Your hair
Light Water-first and light: unlikely to flatten fine hair. Your hair
Fragrance
None listed No fragrance is listed. Your hair
None listed No fragrance is listed. Your hair
Protein Same
Prominent Protein high in the list — a strengthening formula, not a moisture one. Your hair
Prominent Protein high in the list — a strengthening formula, not a moisture one. 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
Moderate Your hair
Moderate 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
Covers the core
Who should choose this
  • Fragrance-freeno fragrance (parfum) on the label
  • Protein-hungry hairthat stretches and stays stretched when wet
  • Fine hairthat flattens under most products
  • Silicone-free routinesno silicones appear in the list
  • Fragrance-freeno fragrance (parfum) on the label
  • Protein-hungry hairthat stretches and stays stretched when wet
  • Fine hairthat flattens under most products
  • Silicone-free routinesno silicones appear in the list
Why you might skip it
  • Protein-sensitive hairthat goes stiff or straw-like on protein
  • Vegan and cruelty-freeour record does not support both claims here
  • Protein-sensitive hairthat goes stiff or straw-like on protein
  • Dry or very humid airwhere heavy humectants work against you
  • Tight budgetsit sits in the upper price tiers
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 treatment
Scalp treatmentserum
Where to buy
—
Brand website
Free of
  • sulfate-free
  • silicone-free
  • fragrance-free
  • curly-method compatible
  • sulfate-free
  • silicone-free
  • fragrance-free
  • curly-method compatible
Cruelty-free
Not cruelty-free · PETA-listed
Cruelty-free · PETA-listed
How often
as needed
as needed

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

IngredientProGrowth + Peptide Hair Strengthening Scalp SerumCurl Therapy Daily Revitalizing Scalp Serum
Water
Neutral
#1Leading
#1Leading
Pentylene Glycol
Moisturizes
#2Leading
#26Below the 1% line
Niacinamide
Detangles
#4Supporting
#7Supporting
Panthenol
Detangles
#6Supporting
#8Supporting

What only one of them carries

ProGrowth + Peptide Hair Strengthening Scalp Serum

Curl Therapy Daily Revitalizing Scalp Serum

Full ingredient list — ProGrowth + Peptide Hair Strengthening Scalp Serum (16)
Full ingredient list — Curl Therapy Daily Revitalizing Scalp Serum (31)

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.

VerdictsProGrowth + Peptide Hair Strengthening Scalp SerumCurl Therapy Daily Revitalizing Scalp Serum
Supported
2
1
Partly supported
0
0
Stated by brand
2
3
Potential conflict
0
0

ProGrowth + Peptide Hair Strengthening Scalp Serum

  • Hydrates scalp to support natural hair growthSupportedHelps hair feel hydrated.
  • Reinforces roots in just 1 use (with full routine)Stated by brandCan’t be confirmed from label.
  • Reduces hair fall due to breakageSupportedReinforces a damaged strand.
  • Fast-absorbing, water-based formulaStated by brandCan’t be confirmed from label.

Curl Therapy Daily Revitalizing Scalp Serum

  • reduces visible grays (MelanoGray)Stated by brandCan’t be confirmed from label.
  • reduces sheddingStated by brandCan’t be confirmed from label.
  • fuller-looking hair in 30 daysStated by brandNot something a label can show.
  • fragrance-freeSupportedSafer for scent-sensitive scalps.

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.

ProGrowth + Peptide Hair Strengthening Scalp Serum

Many reviewers say results were inconclusive after weeks of consistent daily use, with no visible change in hair growth, thickness or density.

A recurring complaint targets the twist/push applicator, which many reviewers find hard to unlock, prone to leaking, or breaking after a short time.

Some reviewers report the serum left hair or scalp feeling greasy, itchy or irritated, and a few describe a small bottle that runs out quickly relative to the price.

Reviewers repeatedly describe the serum as lightweight, fast-absorbing and non-greasy, leaving little to no residue on the scalp.

The fragrance-free formula is appreciated by reviewers with scalp sensitivity, though a few wished it had some scent.

Curl Therapy Daily Revitalizing Scalp Serum

Several reviewers describe the serum as very thick, making it hard to dispense from the dropper and rub into the scalp.

Several early reviewers report positive results such as thicker-feeling hair and fewer visible grays.

Multiple reviewers say it leaves no greasy residue on the scalp or hair when applied correctly.

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.

$22.00/oz vs $34.82/oz — OGX ProGrowth + Peptide Hair Strengthening Scalp Serum costs about 1.6× more per ounce than Ouidad Curl Therapy Daily Revitalizing Scalp Serum.

$1.25/oz median $7.19/oz $55.03/oz $34.82/oz ProGrowth + Peptide Hair S $22.00/oz Curl Therapy Daily Revital

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

Value readProGrowth + Peptide Hair Strengthening Scalp SerumCurl Therapy Daily Revitalizing 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.

ProGrowth + Peptide Hair Strengthening Scalp Serum vs Turmeric Purifying Hair & Scalp MaskBounce Curl · 99% function matchCurl Therapy Daily Revitalizing Scalp Serum vs Revitalizing Detox Scalp ScrubSun Bum · 96% function matchProGrowth + Peptide Hair Strengthening Scalp Serum vs Crown Tonic Pre-Shampoo Scalp-Balancing CleanserDrybar · 99% function matchCurl Therapy Daily Revitalizing Scalp Serum vs Guava & Ginger Scalp Exfoliating Pre-Poo TreatmentCantu · 92% function matchProGrowth + Peptide Hair Strengthening Scalp Serum vs Clean Beauty Scalp Therapy DropsPaul Mitchell · 99% function matchCurl Therapy Daily Revitalizing Scalp Serum vs Rejuvenating Scalp SerumOdele · 88% function matchProGrowth + Peptide Hair Strengthening Scalp Serum vs Scalp Care Scalp Cleansing SerumDesign Essentials · 99% function matchCurl Therapy Daily Revitalizing Scalp Serum vs Grow Long Scalp & Hair SerumMarc Anthony · 83% function match

ProGrowth + Peptide Hair Strengthening Scalp Serum · Curl Therapy Daily Revitalizing 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.
  • 11 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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