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Side by side

Christophe Robin Fortifying Shampoo with Amaranth Peptides vs Rizos Curls Biotin Shampoo

91% function match · 10 of the 13 functions we compared match Formula overlap 26%. Christophe Robin Fortifying Shampoo with Amaranth Peptides and Rizos Curls Biotin Shampoo share 4 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.

  • Fortifying Shampoo with Amaranth Peptides — colour-treated hair
  • Biotin Shampoo — colour-treated hair

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
Christophe Robin

Fortifying Shampoo with Amaranth Peptides

  • Shampoo
  • Prestige
  • Sulfate-free
  • Silicone-free
Rizos Curls Biotin Shampoo — 10 oz container Rizos Curls

Biotin Shampoo

  • Shampoo
  • Masstige
  • Sulfate-free
  • Silicone-free
Price, size & price per ounce
$41 8.4 oz · $4.88/oz
$21.99 10 oz · $2.20/oz
Value / price positioning
Same job for less elsewhere $$$$$ Prestige tier · costs more than 94% of the 817 shampoos we’ve priced
Upper-mid price for a shampoo $$$$$ Masstige tier · costs more than 65% of the 817 shampoos 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 Differs
Low Humectants appear, but low enough to be a minor part. Your hair
Moderate Humectants in the working part of the formula. Your hair
Cleansing strength Same
Moderate Removes oil and product; leaves some conditioning behind. Your hair
Moderate Removes oil and product; leaves some conditioning behind. Your hair
Slip / detangling Same
Moderate Conditioning agents are present, lower in the list. Your hair
Moderate Conditioning agents are present, lower in the list. Your hair
Weight on hair
Light Water-first and light: unlikely to flatten fine hair. Your hair
Medium Middle of the range — noticeable on fine hair, light on coarse hair. Your hair
Fragrance
Present Fragrance is listed; it sits below the working ingredients. Your hair
Present Fragrance is listed; it sits below the working ingredients. 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
Low Your hair
Low Your hair
Expected lather Same
Moderate An ordinary shampoo lather. Your hair
Moderate An ordinary shampoo lather. Your hair
Scalp active Same
None No over-the-counter scalp active. Your hair
None No over-the-counter scalp active. 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
Complete for its job
out of 10
Complete for its job
Who should choose this
  • Colour-treated hairthat fades faster in a sulfate wash
  • Protein-hungry hairthat stretches and stays stretched when wet
  • Curly-method routinesno sulfates and no water-insoluble silicones
  • Hard waterand swimmers dealing with mineral deposit
  • Colour-treated hairthat fades faster in a sulfate wash
  • Protein-hungry hairthat stretches and stays stretched when wet
  • Curly-method routinesno sulfates and no water-insoluble silicones
  • Hard waterand swimmers dealing with mineral deposit
Why you might skip it
  • Scents bother youthis product carries a scent
  • Protein-sensitive hairthat goes stiff or straw-like on protein
  • Tight budgetsit sits in the upper price tiers
  • Scents bother youthis product carries a scent
  • Protein-sensitive hairthat goes stiff or straw-like on protein
  • 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
Shampoo
Shampoo
Line
Fortifying
—
Where to buy
Specialty beauty · Brand website
Brand website
Free of
  • sulfate-free
  • silicone-free
  • curly-method compatible
  • sulfate-free
  • silicone-free
  • curly-method compatible
Cruelty-free
—
Cruelty-free · PETA-listed
Scent
Scented, not described
Scented, not described

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

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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

IngredientFortifying Shampoo with Amaranth PeptidesBiotin Shampoo
Water
Neutral
#1Leading
#1Leading
Sodium Lauroyl Sarcosinate
Cleanses
#3Leading
#3Leading
Phenoxyethanol
Stabilizes
#6Below the 1% line
#32Below the 1% line
Sodium Benzoate
Stabilizes
#8Below the 1% line
#29Below the 1% line
Fragrance
Fragrance
#9Below the 1% line
#22Below the 1% line

What only one of them carries

Fortifying Shampoo with Amaranth Peptides

Biotin Shampoo

Full ingredient list — Fortifying Shampoo with Amaranth Peptides (28)
Full ingredient list — Biotin Shampoo (36)

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.

VerdictsFortifying Shampoo with Amaranth PeptidesBiotin Shampoo
Supported
2
0
Partly supported
0
0
Stated by brand
1
1
Potential conflict
0
0

Fortifying Shampoo with Amaranth Peptides

  • Reduces hair breakage by up to five timesSupportedReinforces a damaged strand.
  • Helps to minimize sheddingStated by brandCan’t be confirmed from label.
  • Leaves hair visibly stronger, resilient, and fullerSupportedReinforces a damaged strand.

Biotin Shampoo

  • Proven to make your hair fuller, softer, shinier and more nourishedStated 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.

Christophe Robin Fortifying Shampoo with Amaranth Peptides draws complaints about how it cleanses and the price.

Fortifying Shampoo with Amaranth Peptides

Reviewers with fine or breakage-prone hair report noticeably less shedding and fuller-feeling hair after using the shampoo as part of the fortifying routine

fine/thin, breakage-prone hair

Some reviewers find the shampoo requires more product per wash than other brands and does not lather heavily

general users comparing to other shampoos

A subset of reviewers felt underwhelmed for the price point, saying results were minimal compared to other prestige shampoos

price-conscious reviewers

Many reviewers evaluate the shampoo jointly with the matching Fortifying Conditioner as a routine rather than reviewing the shampoo alone

reviewers using shampoo+conditioner together

Biotin Shampoo

Leaves hair feeling clean and light after just a couple of uses

Scent is frequently called out as a favorite feature

Cleanses without stripping natural scalp oils, described as gentle on the scalp with daily-ish use

Reviewers report noticeable hair growth and reduced dryness/stagnation over weeks of use

including Spanish-speaking reviewers

Rich lather from a small amount of product; users caution a little goes a long way or hair can feel greasy

curly-hair users

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.

$2.20/oz vs $4.88/oz — Christophe Robin Fortifying Shampoo with Amaranth Peptides costs about 2.2× more per ounce than Rizos Curls Biotin Shampoo.

$0.00/oz median $1.47/oz $17.29/oz $4.88/oz Fortifying Shampoo with Am $2.20/oz Biotin Shampoo

Every mark sits on one distribution because these are compared against the same set: 817 shampoos with a computable unit price.

Value readFortifying Shampoo with Amaranth PeptidesBiotin Shampoo
Label
Same job for less elsewhereYou are paying above the range for a formula close to several lower-priced options.
Upper-mid price for a shampooSits in the middle of the range for shampoos per ounce.

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.

Fortifying Shampoo with Amaranth Peptides vs Apple Cider Vinegar Thin2Thick Clarifying and Detoxing ShampooPura d'or · 92% function matchBiotin Shampoo vs Pure Silk Moisturizing ShampooBounce Curl · 96% function matchFortifying Shampoo with Amaranth Peptides vs Hydrating ShampooMoroccanoil · 89% function matchBiotin Shampoo vs VitalCurl+ Clear & Gentle ShampooOuidad · 93% function matchFortifying Shampoo with Amaranth Peptides vs Signature ShampooOribe · 89% function matchBiotin Shampoo vs TRESemme Cruelty-Free Keratin Smooth Color Sulfate-Free Shampoo for Color-Treated HairTRESemme · 93% function matchFortifying Shampoo with Amaranth Peptides vs 2in1 Thickening Shampoo & ConditionerBosley · 89% function matchBiotin Shampoo vs Simply Smoothing ShampooAcure · 90% function match

Fortifying Shampoo with Amaranth Peptides · Biotin Shampoo · All shampoos 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.
  • 10 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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