The short answer
You can tell whether a hair care product's ingredients are real benefits or marketing by asking what each ingredient does, at what level, and what evidence supports the claim made for it. Cleansing, conditioning, smoothing and reducing breakage are cosmetic effects that can be measured on hair; repair, strengthen and salon quality are only meaningful with a stated test; plant based, essential oils and sulfate free tell you about origin or absence, not performance; and anything that claims to regrow hair, cure dandruff or treat the scalp is medicinal and not a cosmetic claim at all. The ingredient list shows whether a headline ingredient is present at a level that could do anything.
Key takeaways
- Hair is dead protein, so cosmetic hair claims are about the fibre's surface and structure and about the scalp's condition; anything about growth from the follicle is medicinal territory.
- Repair, strengthen and bond claims can be legitimate if a brand can name the test: tensile strength, combing force, breakage counts, or damage repair on treated hair.
- Salon quality, professional and clinical strength have no definition and describe positioning, not performance.
- Plant based, natural and essential oil claims describe origin; essential oils in particular are fragrance and allergens, not treatments.
- Sulfate free and silicone free are absence claims that mean nothing about mildness or results; the replacement ingredients decide those.
- The first six ingredients are the product; a hero ingredient at the end of the list is a marketing garnish.
Hair care has more hero ingredients than any other category: keratin, biotin, argan, bond builders, collagen, caffeine, rice water, rosemary. Most of them appear at the end of the ingredient list, and most of the claims around them are about hair that is already dead. That is not a criticism of the products; it is the starting point for reading them honestly. Hair fibre is keratin with no living cells, so a cosmetic can clean it, coat it, smooth it, temporarily strengthen it and make it easier to comb, and can condition the scalp it grows from, and that is the full menu. Regulation (EU) No 655/2013 requires every claim on a cosmetic to be truthful, evidence based, honest and fair, Regulation (EC) No 1223/2009 and the UK regulation enforced through the Cosmetic Products Enforcement Regulations 2013 draw the line between a cosmetic and a medicine, and the Advertising Standards Authority rules on hair claims regularly.
This guide sorts hair care claims into four kinds, testable, positional, origin and medicinal, and shows how to read each. It explains what hair products can and cannot do, which claims can be measured and how, why salon quality and professional are not claims at all, what plant based and essential oils actually tell you, why sulfate free and silicone free are absence claims, how to spot a hero ingredient at a garnish level, the medicinal claims that should not be on a cosmetic, a worked example of a repair shampoo taken apart, and what a brand should do to make hair claims it can defend. You will finish able to read a shampoo bottle in the time it takes to rinse.
What can a hair care product actually do?The four kinds of hair claim
The hair fibre is a dead keratin structure with an outer cuticle of overlapping scales and an inner cortex. Once it leaves the follicle nothing in it is alive, so nothing applied to it can nourish it in the biological sense, and any change is physical or chemical: cleaning away sebum and residue, depositing conditioning agents that smooth the cuticle and reduce friction, forming films that add shine and protect from heat, penetrating the cortex with small molecules that can temporarily increase strength, and, in bond building products, forming or reinforcing cross links within the fibre. The scalp is living skin and can be cleaned, conditioned, soothed and kept in good condition. That is the complete list of cosmetic effects, and every honest claim maps onto one of them. Growth from the follicle, reversal of hair loss, treatment of scalp conditions and anything affecting the structure or function of the body are medicinal and outside cosmetics law.
The four kinds of hair claim
| Kind |
Examples |
What it needs to be honest |
How to check it |
| Testable performance |
Reduces breakage, easier to comb, adds shine, smooths frizz, strengthens, repairs damage, heat protection |
A stated measurement on the finished product: tensile strength, combing force, breakage count, shine measurement, damage repair on treated tresses |
Ask what was measured, how and on how many samples or people |
| Positional |
Salon quality, professional, clinical strength, stylist approved, luxury |
Nothing, because they describe positioning, not performance; they are lawful if not misleading |
Treat as decoration; look for the testable claim beneath |
| Origin and absence |
Plant based, natural, with essential oils, sulfate free, silicone free, paraben free, clean |
Truthfulness about the origin or absence; no implication of performance or safety |
Read the ingredient list; ask what replaced the absent ingredient |
| Medicinal |
Regrows hair, stops hair loss, treats dandruff, cures scalp conditions, stimulates follicles |
Cannot be made on a cosmetic; the product would be a medicine |
Any such claim means the product is either unlawfully marketed or not a cosmetic |
In practice
Sort every claim on the bottle into one of the four kinds. Only the first kind can be checked. The second is noise, the third is description, and the fourth should not be there.
Which hair claims can be measured, and how?
More than most people expect. Strength is measured by tensile testing of hair fibres before and after treatment. Breakage is measured by counting broken fibres after repeated combing or brushing of treated and untreated tresses. Combability is measured by the force required to comb wet and dry hair. Shine is measured by goniophotometry, which quantifies reflected light. Frizz and smoothness are measured by image analysis of tresses in humidity. Heat protection is measured by fibre damage after repeated heat exposure with and without the product. Repair is the most contested word: it can be measured as restoration of strength or cuticle condition on damaged hair, and a brand claiming repair should say what was damaged, how, and what improved by how much. Colour protection is measured by colour retention after washes. A brand with a real performance claim can name the method in a sentence; a brand without one changes the subject. These are the kinds of hair care claims that can actually be substantiated with data, as opposed to vaguer cosmetic claims that rely on impression rather than measurement.
What do salon quality and professional mean?
Nothing measurable. Salon quality describes an aspiration, professional describes a channel, and neither is a claim about what the product does. They are lawful as positioning provided they do not mislead, and a product sold in supermarkets calling itself professional is at the edge of that. Clinical strength is worse, because it implies a test or a potency that the word alone does not deliver, and a brand using it should be asked which clinic and what strength. When these words appear, look beneath them for the testable claim; if there is none, the words were the product.
What do plant based, natural and essential oils tell you?
They tell you about origin, which is legitimate to state and says nothing about performance or mildness. A plant based shampoo can be harsher than a synthetic one, because the surfactants doing the cleaning may be derived from plants and still be strong cleansers. Essential oils in hair care are fragrance: rosemary, tea tree, peppermint and lavender scent the product and contribute declared allergens, and at cosmetic levels they do not treat the scalp or the hair, whatever the folklore. Claims that an essential oil stimulates growth or treats the scalp are medicinal and should not be on a cosmetic, which is also why hair loss is not something a cosmetic hair care product can claim to treat or prevent. A brand that says with rosemary essential oil for a fresh scent is being honest; a brand that says rosemary oil for thicker hair is not, and the same caution applies to any unsubstantiated claim about hair strength improvements. "Free from" wording on hair care products runs into the same substantiation and fairness issues as elsewhere in cosmetics, and should be approached with the same care. Our guide to natural, organic and chemical free claims covers the origin words in detail.
Why are sulfate free and silicone free absence claims?
Because they describe what is not there, and the effect depends on what is. A sulfate free shampoo uses other surfactants, which may be milder or may not, and the mildness claim belongs to those surfactants, not to the absence. A silicone free conditioner uses other conditioning agents, which may leave hair feeling lighter or rougher depending on the choice. Neither absence is a safety matter: sulfates and silicones are lawful, assessed and widely used. In the UK and EU a free from claim is acceptable only where it gives a consumer genuinely useful information and does not denigrate a lawful ingredient, so sulfate free for someone who prefers a gentler cleanser is acceptable if the product is in fact gentler, and free from harsh sulfates is not.
How do I spot a hero ingredient at a garnish level?
Read the ingredient list in order. In a shampoo the first names are Aqua and two or three surfactants; in a conditioner, Aqua, a fatty alcohol and a conditioning agent. Ingredients listed above one percent are in descending order; below one percent the order is free. A hero ingredient in the first six names is a real component; one after the preservative and the fragrance is present at a fraction of a percent and, in a rinse off product that spends thirty seconds on the hair, is doing very little. Keratin, biotin, collagen and most botanicals appear in this garnish position in the products that name them on the front. That is lawful, provided the claim about them is proportionate, and the assessor checks that an ingredient claimed is present at a level that could do what is claimed. The front of the bottle is not required to be proportionate; the ingredient list tells you whether it is.
Ask yourself
Find the ingredient named on the front of the bottle in the list on the back. If it is after the preservative, the front is marketing. If it is in the first six, ask what it does and whether the claim was tested.
Which hair claims are medicinal?
Anything about growth, loss, follicles or scalp disease. Regrows hair, stops hair loss, thickens thinning hair by stimulating follicles, treats dandruff, cures seborrhoeic dermatitis, treats psoriasis or eczema of the scalp: each is a claim to treat a condition or modify a physiological function, which makes the product a medicine by presentation, and no cosmetic may carry it. Anti dandruff shampoos are the recognised exception: they may be cosmetics if presented as controlling visible flakes and using permitted actives at permitted levels, and become medicines if presented as treating a scalp condition. Products with genuine medicinal actives for hair loss are medicines with marketing authorisations, and a consumer comparing hair loss products by evidence level is comparing medicines with cosmetics, which is a category difference before it is an evidence difference. Our guide to borderline classification draws the line, and a separate guide on hair loss products by evidence level follows in this series.
A worked example: a repair shampoo taken apart
The front says salon quality repair shampoo with keratin and argan oil, sulfate free, plant based, for stronger, healthier hair. Sort the claims. Salon quality is positional. Repair and stronger are testable: the brand's page mentions no test, so they are unsupported. Healthier is a wellbeing word without a measure. With keratin and argan oil is an origin claim: the list shows Hydrolyzed Keratin two places after the preservative and Argania Spinosa Kernel Oil last, so both are garnish. Sulfate free is an absence claim: the surfactants are two glucosides and a betaine, which are milder cleansers, so the absence has a real consequence the brand could have claimed directly. Plant based is an origin claim that the surfactants support. The product is a reasonable mild shampoo whose honest description would be a gentle plant derived cleanser with a light conditioning effect. Its front makes two unsupported performance claims, one empty positional claim and two garnish ingredient claims. Nothing on it is dangerous. Almost nothing on it is evidence.
How does a brand make hair claims it can defend?
- Claim the effect the formula actually delivers. Cleanses gently, conditions, reduces tangling, adds shine.
- Test before claiming performance. Combing force, breakage or tensile tests on the finished product, and say so.
- Put hero ingredients at working levels or drop the claim. An ingredient at a garnish level supports only the words contains.
- Use origin words descriptively. Plant derived surfactants; scented with rosemary essential oil.
- Replace absence claims with positive ones. Formulated with mild glucoside cleansers rather than sulfate free.
- Never touch growth, loss or scalp disease. Those are medicines.
- Keep the claims table in the PIF. One row per claim with its evidence.
Phoenix's claims review sorts a hair product's claims into the four kinds and rewrites the ones that fail, and the free Marketing Claim Checker catches the medicinal ones before they go live.
Myths we hear
- Keratin in a shampoo rebuilds hair. At garnish levels in a rinse off product it does very little; bond building claims need a specific test.
- Essential oils treat the scalp. At cosmetic levels they scent the product and add allergens.
- Sulfate free means gentle. The replacement surfactants decide that.
- Salon quality means tested. It means positioned.
- Natural hair products cannot be harsh. Plant derived surfactants can be strong cleansers.
What to do this week
- Sort every claim on your shampoo and conditioner into the four kinds.
- Find the front of bottle ingredient in the list.
- For each performance claim, ask what was measured.
- If you are a brand, strike every medicinal word from your hair range.
- Replace absence claims with the positive claim they imply.
Hair care claims are easy to read once you know that the hair is dead and the scalp is skin. Everything honest follows from that, and a claims review gets a hair range there before the next print run.
Official sources and legislation
About the author
Phoenix Safety Consultants is a cosmetic compliance consultancy with offices in London, Estonia and Pensacola, Florida. Our safety assessors and toxicologists prepare Cosmetic Product Safety Reports, Toxicological Risk Assessments, Product Information Files, Safety Data Sheets and UK and EU notifications for brands of every size. Talk to the team on WhatsApp at +44 7346 009332 or at Compliance@phoenixcosmeticsafety.com.
Disclaimer: This article is general information, not legal advice. Regulations change and product decisions depend on your exact formulation, claims and market. Have your product assessed by a qualified professional before sale.
Frequently Asked Questions
How can I tell if a hair care product's ingredients are just marketing?
Find the front of bottle ingredient in the list on the back. If it appears after the preservative it is present at a fraction of a percent and, in a rinse off product, does very little. Then ask what test supports any performance claim; a brand with real evidence can name the measurement.
What can a hair care product actually do?
Clean the hair, deposit conditioning agents that smooth the cuticle, form films that add shine and protect from heat, temporarily increase fibre strength, reinforce bonds in bond building products, and clean and condition the scalp. Growth from the follicle and treatment of scalp conditions are medicinal, not cosmetic.
Are repair and strengthen legitimate hair claims?
They can be, if the brand can name the test: tensile strength, combing force, breakage counts or damage repair measured on treated hair. Without a stated measurement they are unsupported.
What does salon quality mean?
Nothing measurable. It describes positioning, not performance, and is lawful only if it does not mislead. Look beneath it for a testable claim.
Do essential oils in hair care do anything?
At cosmetic levels they scent the product and contribute declared allergens. Claims that an essential oil stimulates growth or treats the scalp are medicinal and should not appear on a cosmetic.
Is sulfate free shampoo gentler?
Only if the replacement surfactants are milder, which is a claim about them rather than about the absence. Sulfates are lawful and assessed; free from claims that imply otherwise are unfair under UK and EU rules.
Which hair claims make a product a medicine?
Regrows hair, stops hair loss, stimulates follicles, treats dandruff, cures scalp conditions or anything affecting the structure or function of the body. Anti dandruff shampoos may be cosmetics only if presented as controlling flakes with permitted actives.
How should a brand make hair claims it can defend?
Claim the effects the formula delivers, test before making performance claims and state the test, put hero ingredients at working levels or drop the claim, use origin words descriptively, replace absence claims with positive ones, avoid medicinal language, and keep a claims table in the PIF.
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