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CONDITIONER

How to use conditioner properly

The short answer

Conditioner coats the hair so strands slide past each other. Use it after every shampoo on mid-lengths and ends, not the roots. It smooths hair and cuts breakage. It does not repair damage.

See how it works

Shampoo is for the scalp, where sebum builds up; the suds rinse down the lengths. Conditioner goes on mid-lengths and ends, which are older and more worn than the roots. Shaw 1979 ↗ Labarre 2023 ↗ Thibaut 2010 ↗
The usual order of a wash day. Conditioner before detangling cut the chance of a damaging snag on wet bleached hair from 100% to under 10%, and wet hair is weakest, so towel and heat come last. New 2018 ↗ Robbins 2007 ↗ Lee 2011 ↗

Do this

  1. 1Shampoo first, squeeze out the water, then apply conditioner.
  2. 2Cover mid-lengths and ends. Keep it off an oily scalp.
  3. 3Comb it through gently, ends first, while the conditioner is on.
  4. 4Leave it a minute or two, then rinse well.
  5. 5Dry or curly? Add a little leave-in on damp ends.
  6. 6Hair feels coated or limp? Use a clarifying (deep-cleaning) wash now and then.

The numbers behind it

  • 100% to under 10%

    Chance of a damaging snag when combing wet bleached hair fell from 100% to under 10% with conditioner (lab hair bundles).

  • Fewer breaks

    A commercial conditioner reduced both short and long hair breaks during combing of bleached hair bundles (lab).

  • Smooths, not repairs

    In a lab test, conditioner ingredients cut combing force but did not undo bleach-type (oxidative) damage.

  • Not absorbed

    Expert safety panel: dimethicone (a common silicone) is not absorbed through skin and is safe in cosmetics as used (up to 15%).

For your hair

  • Curly, coily or bleached hair

    Rougher, damaged hair snags more, so conditioner matters most. Use a richer one and detangle with it.

  • Fine or low-density hair

    Use a light conditioner on the ends only. Heavy formulas can weigh hair down.

  • Oily scalp

    Start the conditioner at ear level. Rinse thoroughly.

Myths to ignore

  • Myth Conditioner repairs split ends and damage.

    Truth It lubricates and smooths the surface. In the lab it improved combing but left the damaged structure unchanged. Only a trim removes a split end.

    Tham 2026 ↗
  • Myth Silicones suffocate hair and should be avoided.

    Truth Hair is dead tissue, so nothing suffocates. Silicones cut friction and add shine. Water-insoluble types can build up; an occasional clarifying (deep-cleaning) wash fixes it.

    Carvalho 2025 ↗
  • Myth Silicone-free conditioners cannot work.

    Truth On bleached hair, silicone-free emulsions partly or fully restored the water-repelling surface, similar to a silicone formula. Lab study by an ingredient supplier.

    Liu 2022 ↗

Made for this

Go deeper

All studies in this guide (6)

New S et al. Measuring the frequency of consumer hair combing and magnitude of combing forces on individual hairs in a tress and the implications for product evaluation and claims substantiation. 2018

Design
other
People
231
Who
Asian and Caucasian women, survey plus tress combing

Result: Women combed about 16 strokes a day; wet bleached hair snagged every time and conditioner cut that to under 10%.

Read the study ↗

Robbins C et al. Hair breakage during combing. III. The effects of bleaching and conditioning on short and long segment breakage by wet and dry combing of tresses. 2007

Design
other
Who
hair tresses

Result: Dry combing breaks the ends more per stroke; wet combing breaks hair higher up; conditioner reduced both short and long breaks.

Read the study ↗

Tham HP et al. Electrokinetic analysis reveals common conditioner ingredient interactions with human hair. Int J Cosmet Sci. 2026

Design
in vitro
Who
human hair and silica surfaces (A*STAR Singapore, Ashland co-author)

Tested: behentrimonium chloride and methosulfate, cetrimonium chloride, stearalkonium chloride

Result: Longer-chain behentrimonium chloride cut wet combing force and deposited best; none reversed oxidative damage.

Read the study ↗

Nair B, Cosmetic Ingredient Review Expert Panel. Final report on the safety assessment of stearoxy dimethicone, dimethicone, methicone, amino bispropyl dimethicone, aminopropyl dimethicone, amodimethicone, and related silicones. Int J Toxicol. 2003

Design
review

Result: The panel judged dimethicone and the amino-silicones safe as used in cosmetics, with minimal absorption.

Read the study ↗

Carvalho RM, Melo DF, Kelati A, Tosti A. With or without silicones? A comprehensive review of their role in hair care. Skin Appendage Disord. 2025

Design
review

Tested: silicones in hair care

Result: Silicones reduce friction, prevent moisture loss and add shine and heat protection, with build-up concerns for water-insoluble types; newer water-dispersible forms exist.

Read the study ↗

Liu Z et al. Effects of cosmetic emulsions on the surface properties of Mongolian hair. ACS Omega. 2022

Design
in vitro
Who
bleached and untreated hair, BASF-affiliated laboratory

Result: Bleaching raised wettability and friction; emulsions containing conditioning agents restored water repellency and reduced combing work.

Read the study ↗