Skip to main content

Side by side

CHI Royal Treatment Volume Shampoo vs K18 DAMAGE SHIELD pH Protective Shampoo

96% function match · 12 of the 13 functions we compared match Formula overlap 53%. CHI Royal Treatment Volume Shampoo and K18 DAMAGE SHIELD pH Protective 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.

  • Royal Treatment Volume Shampoo — colour-treated hair
  • DAMAGE SHIELD pH Protective 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
CHI Royal Treatment Volume Shampoo — 12 oz container CHI

Royal Treatment Volume Shampoo

  • Shampoo
  • Salon
  • Sulfate-free
  • Silicone-free
K18 DAMAGE SHIELD pH Protective Shampoo — 8.5 oz container K18

DAMAGE SHIELD pH Protective Shampoo

  • Shampoo
  • Prestige
  • Sulfate-free
  • Silicone-free
Price, size & price per ounce
$23 12 oz · $1.53/oz
$37–39 8.5 oz · $4.59/oz
Value / price positioning
Upper-mid price for a shampoo $$$$$ Salon tier · costs more than 51% of the 817 shampoos we’ve priced
Same job for less elsewhere $$$$$ Prestige tier · costs more than 93% 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 Same
Moderate Humectants in the working part of the formula. Your hair
Moderate Humectants in the working part of the formula. Your hair
Cleansing strength Same
Strong Removes oil, buildup, and most residue — a reset wash. Your hair
Strong Removes oil, buildup, and most residue — a reset wash. 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
Medium Middle of the range — noticeable on fine hair, light on coarse hair. Your hair
Light Water-first and light: unlikely to flatten fine 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
Minor Protein appears, low enough to be a supporting ingredient. Your hair
Minor Protein appears, low enough to be a supporting ingredient. 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
High Thick foam that spreads quickly through the hair. Your hair
High Thick foam that spreads quickly through the hair. 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
  • Fast-oiling scalpsthat need a real reset wash
  • Dry, thirsty hairhumectants and emollients both sit up front
  • Curly-method routinesno sulfates and no water-insoluble silicones
  • Colour-treated hairthat fades faster in a sulfate wash
  • Fast-oiling scalpsthat need a real reset wash
  • 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
  • Dry or damaged haira strong detergent system strips as it cleans
  • Tight budgetsit sits in the upper price tiers
  • Scents bother youthis product carries a scent
  • Dry or damaged haira strong detergent system strips as it cleans
  • 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
Shampoo
Shampoo
Line
—
DAMAGE SHIELD
Where to buy
Brand website · Beauty Supply Retail
Brand website · Sephora · Ulta
Free of
  • sulfate-free
  • silicone-free
  • curly-method compatible
  • sulfate-free
  • silicone-free
  • curly-method compatible
Cruelty-free
—
Cruelty-free · brand states
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

$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

IngredientRoyal Treatment Volume ShampooDAMAGE SHIELD pH Protective Shampoo
Water
Neutral
#1Leading
#1Leading
Sodium C14-16 Olefin Sulfonate
Cleanses
#2Leading
#2Leading
Cocamidopropyl Betaine
Cleanses
#3Leading
#3Leading
Caprylyl Glycol
Moisturizes
#7Below the 1% line
#12Below the 1% line
Fragrance
Fragrance
#32Below the 1% line
#18Below the 1% line
Panthenol
Detangles
#14Below the 1% line
#7Supporting
Glycerin
Moisturizes
#21Below the 1% line
#8Supporting
Limonene
Fragrance
#34Below the 1% line
#19Below the 1% line

What only one of them carries

Royal Treatment Volume Shampoo

DAMAGE SHIELD pH Protective Shampoo

Full ingredient list — Royal Treatment Volume Shampoo (35)
Full ingredient list — DAMAGE SHIELD pH Protective Shampoo (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.

VerdictsRoyal Treatment Volume ShampooDAMAGE SHIELD pH Protective Shampoo
Supported
0
0
Partly supported
3
0
Stated by brand
1
1
Potential conflict
0
0

Royal Treatment Volume Shampoo

  • Boosts hair's strength and elasticityStated by brandCan’t be confirmed from label.
  • Enhances shinePartly supportedA hint of gloss.
  • Imbues fine, flat hair with extra body and bouncePartly supportedNeutral on lift.
  • This lightweight cleanser plumps fine, flat hair with volumePartly supportedNeutral on lift.

DAMAGE SHIELD pH Protective Shampoo

  • Clinically proven to provide conditioning protection against damage from UV rays, mechanical styling, and environmental aggressors for up to 3 daysStated 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 the scent.

Royal Treatment Volume Shampoo

Fragrance is repeatedly called out as a highlight ("smells wonderful"/"divine")

general reviewers

Reviewers with fine, curly hair report a noticeable increase in volume and body without weigh-down

self-described senior with fine, long, curly hair

Long-time CHI Royal Treatment users express strong repeat-purchase loyalty across the shampoo/conditioner pair

multi-year CHI Royal Treatment customer

DAMAGE SHIELD pH Protective Shampoo

Pleasant scent called out repeatedly as a selling point

general users

Reported to visibly repair brittle, dry, or chemically damaged hair over a few weeks of use

users with color-treated/bleached or heat-damaged hair

Leaves hair clean and soft without feeling weighed down

general users, several noting fine or fine-to-medium hair

Some reviewers pair it explicitly with the leave-in mask and report better results using the full system rather than the shampoo alone

repeat/multi-product K18 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.

$1.53/oz vs $4.59/oz — K18 DAMAGE SHIELD pH Protective Shampoo costs about 3× more per ounce than CHI Royal Treatment Volume Shampoo.

$0.00/oz median $1.48/oz $17.29/oz $1.53/oz Royal Treatment Volume Sha $4.59/oz DAMAGE SHIELD pH Protectiv

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

Value readRoyal Treatment Volume ShampooDAMAGE SHIELD pH Protective Shampoo
Label
Upper-mid price for a shampooSits in the middle of the range for shampoos per ounce.
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.

Royal Treatment Volume Shampoo vs Luxe Shine ShampooKenra Platinum · 98% function matchDAMAGE SHIELD pH Protective Shampoo vs Amino Bond Shampoo For DamagedNexxus · 96% function matchRoyal Treatment Volume Shampoo vs Amino Bond Shampoo For DamagedNexxus · 98% function matchDAMAGE SHIELD pH Protective Shampoo vs PEPTIDE PREP Detox ShampooK18 · 96% function matchRoyal Treatment Volume Shampoo vs Miracle Volumizing Daily ShampooIt's a 10 · 98% function matchDAMAGE SHIELD pH Protective Shampoo vs Miracle Volumizing Daily ShampooIt's a 10 · 96% function matchRoyal Treatment Volume Shampoo vs PEPTIDE PREP Detox ShampooK18 · 96% function matchDAMAGE SHIELD pH Protective Shampoo vs Luxe Shine ShampooKenra Platinum · 95% function match

Royal Treatment Volume Shampoo · DAMAGE SHIELD pH Protective 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.

Still unsure? Take your consultation or browse more products.

Your personalized hair plan

Tell us what’s going on with your hair, see what we understand, and get a plan built around it — with the reason behind every recommendation.

Free to start · $49.00 for your consultation and hair profile · No subscription · Nothing you must buy

Start your consultation