Overnight Hair Repair

In the US, ingredients above 1% are listed from most to least. Below 1% they can appear in any order. Each note keeps three things apart: what the ingredient generally does, its role in this type of product, and what its position can tell you.

• 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 Cyclopentasiloxane
  General function

  A light, fast-evaporating silicone that spreads other ingredients then leaves. It gives serums their weightless glide.

  Leading ingredient

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

  May suitBuild-up-sensitive routines

  It leaves the hair by evaporating rather than by being washed off, so it is not part of what accumulates.

  May suitClimate-sensitive or frizz-prone hair

  A surface film slows how quickly humidity reaches the cortex, which is what limits swelling-driven frizz in damp air.

  May suitFine or easily flattened hair

  A cyclic silicone evaporates after it has spread the formula, so it carries the other ingredients without leaving weight behind.

  PubChem
  • silicone
  • emollient
• 3 Glycerin
  General function

  Glycerin, also called glycerol, attracts moisture and mixes completely with water.

  Leading ingredient

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

  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
• 4 Dimethicone
  General function

  The most common conditioning silicone. It coats the strand for shine, slip, and frizz control, and needs a detergent (not just water) to wash out.

  Supporting ingredient

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

  May suitClimate-sensitive or frizz-prone hair

  A surface film slows how quickly humidity reaches the cortex, which is what limits swelling-driven frizz in damp air.

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

  Lays a smooth film along the cuticle, which lowers combing friction and flattens the surface irregularities that read as frizz.

  May not suitBuild-up-sensitive routines

  Dimethicone does not disperse in water. On a routine that skips detergent it stays on the hair and accumulates wash after wash.

  • silicone
  • emollient
  • conditioning agent
• ▾Below about here, the order stops meaning much. These are usually used at 1% or less.
• 5 Fragrance · Parfum (Fragrance)
  General function

  An undisclosed blend of scent ingredients. Regulations let it stay unlisted, so a fragrance-free product is the only way to be certain what is not in it.

  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 not suitFragrance-sensitive routines

  Declared fragrance. On a fragrance-sensitive routine this is the line that decides it, wherever it sits on the label.

  • fragrance
  • declared fragrance
• 6 Hydrolyzed Rhodophycea (Red Algae) Extract
  General function

  A broken-down red-algae extract used for moisture binding and film-forming claims.

  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
  • humectant
• 7 Carrageenan · Chondrus Crispus (Carrageenan) Extract
  General function

  A seaweed gum that thickens and adds slip.

  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 suitCurls or waves needing flexible hold

  Gums thicken and set soft, which gives definition that bends rather than a rigid cast.

  • gum
  • thickener
• 8 Phenoxyethanol
  General function

  The most common modern preservative; it keeps the product free of bacteria and mould. It sits well below 1% of the formula.

  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.

  PubChem
  • preservative
• 9 glyceryl acrylate/acrylic acid copolymer
  • film former
  • polymer
• 10 Propylene Glycol
  General function

  A small humectant and solvent that keeps formulas stable and helps active ingredients spread.

  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 suitFine or easily flattened hair

  Light and water-binding rather than oily, so it adds less weight than oils or butters do.

  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
• 11 Acrylates/C10-30 Alkyl Acrylate Crosspolymer
  General function

  A gel-forming thickener that also keeps oils suspended. It contributes a little hold.

  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 suitClimate-sensitive or frizz-prone hair

  A set polymer film is a physical barrier to humidity, so a style keeps its shape longer in damp conditions.

  May suitMaximum-hold styling

  Synthetic film formers dry into a continuous film, which is what holds a shape against movement and against humid air.

  DependsBuild-up-sensitive routines

  Some acrylate copolymers rinse with water and some need a detergent; the label alone does not say which one a formula used.

  • thickener
  • polymer
  • film former
• 12 PEG-40 Hydrogenated Castor Oil
  • solubilizer
  • emulsifier
• 13 Aminomethyl Propanol
  General function

  A base used in trace amounts to neutralise acidic hold polymers so they thicken and set properly.

  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.

  DependsFrizz-prone, damaged, or high-friction hair

  pH adjusters are how a formula is brought to a chosen acidity, and an acidic formula keeps the cuticle lying flatter than an alkaline one. Which way this one moves the pH depends on the formula, and the finished pH is not on the label.

  PubChem
  • pH adjuster
• 14 Ethylhexylglycerin
  General function

  A preservative booster that also adds a little softness. Almost always paired with phenoxyethanol.

  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 suitFrizz-prone, damaged, or high-friction hair

  Emollients fill and smooth the surface of the strand, which lowers the friction that lifts the cuticle and reads as roughness.

  PubChem
  • preservative
  • emollient
• 15 Citronellol
  General function

  A rose-like fragrance component named separately as a recognised allergen.

  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 not suitFragrance-sensitive routines

  One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

  PubChem
  • fragrance
  • named fragrance allergen
• 16 Limonene
  General function

  A citrus-smelling fragrance component that EU rules require to be named separately because some people react to it.

  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 not suitFragrance-sensitive routines

  One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

  PubChem
  • fragrance
  • named fragrance allergen
• 17 Geraniol
  General function

  A rose-scented fragrance component, listed on its own because some people react to it.

  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 not suitFragrance-sensitive routines

  One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

  • fragrance
  • named fragrance allergen
• 18 Hexyl Cinnamal
  General function

  A jasmine-like fragrance component named separately as a recognised allergen.

  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 not suitFragrance-sensitive routines

  One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

  PubChem
  • fragrance
  • named fragrance allergen
• 19 Linalool
  General function

  A floral fragrance component listed separately as a recognised contact allergen.

  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 not suitFragrance-sensitive routines

  One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

  PubChem
  • fragrance
  • named fragrance allergen

What the whole list adds up to

• 6 fragrances
• 5 named fragrance allergens
• 3 emollients
• 3 humectants
• 2 solvents
• 2 silicones
• 2 thickeners
• 2 preservatives
• 2 film formers
• 2 polymers
• 1 conditioning agent
• 1 declared fragrance
• 1 botanical extract
• 1 gum

Ingredient list captured 2026-08-24. Formulas change, so check the package in your hand when an ingredient matters to you.