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Haircare · 5 min read

How to read a shampoo ingredient list

Most shampoo ingredients do one of five jobs: clean, condition, thicken or balance the formula, preserve it, or add scent. Find the cleansers just after water, then the conditioning agents, then the small print. Read "sulfate-free" or "silicone-free" as a description of what was left out, not a promise about how the shampoo will feel.

Checked against 6 sources on 10 October 2026. How guides are written

A typical list, sorted by job

A shampoo's list, annotated

Ingredients: Aqua, Sodium Laureth Sulfate, Cocamidopropyl Betaine, Sodium Chloride, Glycerin, Panthenol, Polyquaternium-10, Citric Acid, Sodium Benzoate, Parfum, Limonene.

  1. AquaDissolves other ingredients
  2. Sodium Laureth SulfateCleanses and foams
  3. Cocamidopropyl BetaineCleanses and foams
  4. Sodium ChlorideGives the texture
  5. GlycerinHelps attract water
  6. PanthenolKeeps skin in good condition
  7. Polyquaternium-10Forms a light film
  8. Citric AcidBalances the pH
  9. Sodium BenzoateKeeps the formula fresh
  10. ParfumAdds scent
  11. LimoneneAdds scent

An illustrative list, not a real product. Each role is the ingredient's main function from the EU database, as the app ranks them.

Cleansers come first

After water, the first names are usually surfactants: ingredients that let water lift away oil and dirt, and make lather. Sodium Laureth Sulfate is a common one, often paired with a second surfactant such as Cocamidopropyl Betaine.

Similar names are not the same ingredient. In patch tests, sodium lauryl sulfate (SLS) irritated skin markedly more than sodium laureth sulfate (SLES) at the same concentrations.1 And for SLES, US reviewers found that whether it irritates in practice depends on the formula it is in.2

Then the conditioning agents

These change how hair feels and behaves after washing. Panthenol is a hair conditioning agent3; polymers such as Polyquaternium-10 form a light film and reduce static; silicones such as Amodimethicone condition hair and reduce static. In a shampoo they usually come after the cleansers.

The ingredients that hold the formula together

  • Thickeners: Sodium Chloride, ordinary salt, often thickens a shampoo made with these surfactants.
  • pH and stability: Citric Acid adjusts acidity and helps keep the formula stable.
  • Preservatives: a product that contains water needs protecting from microbes. In the EU only preservatives on an approved list (Annex V) may be used, each within its own limits. Sodium Benzoate and Salicylic Acid both appear on it.45

Scent, and the names after it

Parfum covers the whole scent mixture. Because shampoo is rinsed off, EU labels must name a fragrance allergen separately only above 0.01%, ten times the threshold for a leave-on product.6 That is why names such as Limonene or Linalool can follow Parfum on one shampoo and not on another.

Sulfate-free, silicone-free

These claims describe what was left out. They do not tell you what replaced it, how much cleanser there is, or how the shampoo will suit your scalp. The list does: look at the first few names after water to see which cleansers were chosen.

A list is not a concentration chart and not a verdict. Formulas also change over time, so check the list on the bottle you actually have.

Sources

  1. Löffler H, Happle R. Profile of irritant patch testing with detergents: sodium lauryl sulfate, sodium laureth sulfate and alkyl polyglucoside. Contact Dermatitis 2003;48(1):26-32. pubmed.ncbi.nlm.nih.gov Checked 10 October 2026.
  2. Robinson VC, et al. Final report of the amended safety assessment of sodium laureth sulfate and related salts of sulfated ethoxylated alcohols. International Journal of Toxicology 2010;29(4 Suppl):151S-61S. pubmed.ncbi.nlm.nih.gov Checked 10 October 2026.
  3. Scott LN, et al. Safety assessment of panthenol, pantothenic acid, and derivatives as used in cosmetics. International Journal of Toxicology 2022;41(3 suppl):77-128. pubmed.ncbi.nlm.nih.gov Checked 10 October 2026.
  4. Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products, consolidated text of 1 May 2025, Articles 14, 19 and 33. Official Journal of the European Union. eur-lex.europa.eu Checked 10 October 2026.
  5. Commission Regulation (EU) 2019/1966 of 27 November 2019 amending and correcting Annexes II, III and V to Regulation (EC) No 1223/2009 (salicylic acid: Annex III entry 98, Annex V entry 3). eur-lex.europa.eu Checked 10 October 2026.
  6. Commission Regulation (EU) 2023/1545 of 26 July 2023 amending Regulation (EC) No 1223/2009 as regards labelling of fragrance allergens in cosmetic products. eur-lex.europa.eu Checked 10 October 2026.

Written for this site from the sources above and checked against them on 10 October 2026. Not reviewed by a dermatologist or toxicologist, and not medical advice. Spotted something wrong? Tell us.