Silicones and Sulfates: Are They Bad for Your Hair?
11 min read Care know-how Updated 5 October 2026 By Anna Sophie Schulenburg
Silicones and sulfates only become bad for your hair when they don't suit your scalp and your lengths; for most hair, both are perfectly safe. So read the INCI lists of your shampoo and conditioner together. A sulfate, which is a strong cleansing agent, is often too much for a dry, sensitive scalp, and a clinging silicone, which wraps a smoothing film around the fibre, turns into a coating when the shampoo next to it is very mild. You'll know the mix is right after two or three washes: your scalp stays calm and your lengths fall smooth without turning heavy or stringy.
What sulfates do when you wash
Sulfates belong to the surfactants. These are molecules with one oil-loving and one water-loving end: they wrap around sebum, oil and styling residue and make them rinsable. The best known is Sodium Lauryl Sulfate, or SLS for short. It lathers heavily, strips oil thoroughly and serves as a test substance in skin research whenever irritation is being studied. Sodium Laureth Sulfate, or SLES, sounds almost identical. An added molecular chain makes it considerably milder, though, and in many supermarket shampoos it is listed straight after water.
A shampoo's cleansing strength depends on more than its sulfate. Co-surfactants such as Cocamidopropyl Betaine soften it, the amount plays a part, and the lather only stays on your scalp for one to two minutes. An oily scalp usually copes well with a sulfate shampoo, even with daily washing. A dry or sensitive scalp is more likely to react with tightness and fine flakes, especially when hot water is involved.
What silicones do in your hair
Silicones are film formers. They wrap around the fibre, smooth the lifted edges of the cuticle and reduce friction between the hairs. Your comb glides through more easily, light is reflected more evenly, and humid air gets in more slowly, so fewer small hairs stick up. That's why they are standard in heat protectants and shine serums.
How long a silicone stays in your hair depends on the type. Volatile silicones such as Cyclopentasiloxane, known as D5 in the environmental debate, make a product spread easily and then evaporate, so hardly any of it remains in your hair. Water-soluble versions, recognisable by “PEG-” or “PPG-” in the name, rinse out even with a mild shampoo. Dimethicone clings more firmly and comes off more easily with a strong surfactant than with a very mild one. Amodimethicone settles mainly on damaged areas, because their surface attracts it, and it holds especially well there.
None of this repairs anything. A split end stays split; it simply lies flatter under the film until the next wash wears it away.
Are silicones and sulfates bad for your hair? Myths fact-checked
| Claim | Verdict | Why |
|---|---|---|
| Silicones suffocate your hair | No | The lengths are made of dead keratin and don't breathe; the film sits on the outside of the fibre |
| Silicones dry hair out | No | If anything, the film slows down water evaporating from the fibre; hair feels dull and straw-like when a coating has built up on it over weeks |
| Silicones clog the pores on your scalp | No evidence | Dimethicone counts as non-comedogenic in skincare too; roots look greasy when conditioner reaches the scalp |
| Silicones only fake healthy hair | Partly | The smoothness and easy combing are real while the film lasts; split ends and breakage remain underneath |
| Sulfates cause hair loss | No evidence | The hairs in the drain had usually come loose already and simply leave together while you massage; there is no study showing that sulfates cause hair loss |
| Sulfate-free automatically means mild | No | Substitute surfactants such as Sodium C14-16 Olefin Sulfonate strip oil barely less than SLS |
| Sulfates wash out hair colour | Partly | Strong surfactants pull a little more colour out of the fibre; hot water and daily washing contribute at least as much |
| Silicones harm the environment | For some types, yes | The volatile silicones D4 and D5 break down poorly in water; since 2020, rinse-off cosmetics in the EU may only contain traces of them, and the EU is extending the rule to leave-on products |
If your hair falls out in clumps or you find round bald patches, don't look for the cause in your shampoo. That's one for a dermatologist, because the trigger sits at the root, where no shampoo or conditioner can reach.
Sulfate-free shampoo or silicone-free care: what your hair needs
Your scalp decides on the shampoo; your lengths decide on conditioner and leave-in (the product that stays in your hair after washing). Find the row that best matches what you notice after a wash.
| What you notice | Sulfates in shampoo | Silicones in conditioner and leave-in |
|---|---|---|
| Roots get oily after a day, lengths are easy-going | a good fit | a little, ends only |
| Scalp feels tight after washing, fine dry flakes | choose milder surfactants | in the lengths as needed |
| Fine hair already falls flat after conditioner | fine, especially if you wash often | only easy-rinse types, from chin level down |
| Curly or coily hair with dry lengths | mild surfactants, a clarifying wash every few weeks | welcome, as long as your shampoo can lift them off again |
| Coloured or bleached hair | milder surfactants and lukewarm water | helpful for smoothing damaged lengths |
| Hair feels heavy, dull and coated despite conditioning | clarify once, then carry on as usual | use less or switch to lighter types |
| Freshly keratin-smoothed | sulfate-free, as your hairdresser advises | in the lengths as needed |
The milder your shampoo, the lighter the silicones in the rest of your routine should be. A sulfate also removes Dimethicone. A shampoo built only on sugar surfactants such as Coco-Glucoside manages that less well, and a little more film can then stay behind with every conditioner.
Do two rows fit you, say a tight scalp and lengths that crave smoothness? The free hair analysis asks about your scalp, hair thickness and care habits one by one.
How to spot silicones and sulfates on the INCI list
The INCI list is the ingredients list on the back of the bottle, using standardised names across the EU, mostly English or Latin. Four steps let you read it in a minute.
Step 1 — Read the first five names. Ingredients are listed by amount, largest first. Only those below one per cent may follow at the end in any order. The first five names set the character of the product, and in a shampoo the main surfactant almost always comes straight after Aqua.
Step 2 — Place the main surfactant. If “Sulfate” is part of the name, it's a sulfate. “Lauryl” without “eth” cleanses strongly, “Laureth” a little more mildly. If a betaine or a glucoside follows, it softens the cleansing.
Step 3 — Spot silicones by their ending. Names ending in “-cone”, “-conol” or “-siloxane” are silicones. A “PEG-” or “PPG-” in front means water-soluble; “Cyclo-” usually means volatile.
Step 4 — Look for the other film formers. Polyquaternium, Guar Hydroxypropyltrimonium Chloride, shea butter (Butyrospermum Parkii Butter) and beeswax (Cera Alba) stay on the hair as well. If you only look for residue among the silicones, you miss this group.
This is how it looks on a typical conditioning shampoo from the supermarket. The list is an example and belongs to no particular product:
Aqua, Sodium Laureth Sulfate, Cocamidopropyl Betaine, Sodium Chloride, Glycerin, Dimethicone, Guar Hydroxypropyltrimonium Chloride, Parfum, Citric Acid, Sodium Benzoate
Sodium Laureth Sulfate in second place is the main surfactant, a sulfate of the milder kind, and the betaine after it softens it further. Dimethicone is a clinging silicone, the guar derivative a second film former. For an oily scalp, this is an uncomplicated everyday shampoo. On fine hair that you wash daily and then condition with a silicone conditioner, it can weigh things down over time. A shampoo with “sulfate-free” on the front, on the other hand, sometimes starts with Aqua, Sodium C14-16 Olefin Sulfonate, Cocamidopropyl Betaine. Chemically, the olefin sulfonate isn't a sulfate, yet it cleanses almost as thoroughly as SLS.
| Group | Typical INCI names | What it means for you |
|---|---|---|
| Strong sulfates | Sodium Lauryl Sulfate, Ammonium Lauryl Sulfate, Sodium Coco-Sulfate | thorough, suits an oily scalp; Coco-Sulfate sounds natural and cleanses about as strongly as SLS |
| Milder sulfates | Sodium Laureth Sulfate, Ammonium Laureth Sulfate | fine for everyday use for most people, milder still with a betaine alongside |
| Sulfate-free yet strong | Sodium C14-16 Olefin Sulfonate | may be labelled “sulfate-free” and still cleanses strongly |
| Mild surfactants | Cocamidopropyl Betaine, Coco-Glucoside, Decyl Glucoside, Sodium Cocoyl Isethionate, Sodium Cocoyl Glutamate | for dry and sensitive scalps; lift clinging silicones less well |
| Easy-rinse silicones | PEG-12 Dimethicone, PEG/PPG-18/18 Dimethicone, Cyclopentasiloxane, Cyclomethicone | hardly any residue, even with a mild shampoo |
| Clinging silicones | Dimethicone, Dimethiconol, Amodimethicone, Bis-Aminopropyl Dimethicone | lots of smoothness; with mild washing, clarify every two to four weeks |
| Other film formers | Polyquaternium-10, Guar Hydroxypropyltrimonium Chloride, Butyrospermum Parkii Butter, Cera Alba | can build up just like silicones |
Formulas change from time to time. What counts is always the list on the bottle you are holding.
When to leave out sulfates or silicones
Leave out strong sulfates if your scalp feels tight or itchy after every wash and stays that way even with lukewarm water. The same goes after a keratin treatment for which the salon prescribes sulfate-free shampoo. Whether an itchy scalp after shampooing comes from the surfactant or the fragrance is something you find out by swapping one product at a time. If your scalp burns, turns red or weeps, see a dermatologist, because persistent irritation can come from eczema or a contact allergy that a milder shampoo won't treat.
Cut back on clinging silicones if your fine hair quickly falls flat, and whenever you wash exclusively with mild surfactants. Curly hair is the best-known case. The Curly Girl Method drops sulfates and non-water-soluble silicones together, because without a strong surfactant nothing should go onto the hair that only a strong surfactant can remove. How you care for curls and waves without them turning straw-like then comes down mainly to conditioner and leave-in. With coloured hair, keep the two questions apart. Milder surfactants and lukewarm water wash out less colour, and silicones in the lengths smooth the rough surface that colour and bleach leave behind. How you look after colour-treated hair between appointments also depends on heat and on how often you wash.
If your hair feels dull, heavy and coated straight after washing, there is usually a film of silicones, polymers, limescale or styling product on it. How you clear product build-up from hair and scalp depends on where it comes from; one or two clarifying washes are often enough.
The most common mistakes and what to do instead:
- Buying shampoo because it says “sulfate-free” on the front → read the first five INCI names
- Mild shampoo plus a Dimethicone conditioner, without ever clarifying → a clarifying wash every two to four weeks, or a conditioner with lighter silicones
- Silicone conditioner right up to the roots → only from ear level down, on lengths and ends
- Judging after a single wash → compare two or three washes using the same amount
If you use MONAT
MONAT describes its shampoos as free of SLS and SLES. Whether a particular product contains silicones is shown on its INCI list, and the table above lets you place them yourself. The Advanced Hydration Shampoo is designed for fine to medium, dry hair, the Renew™ Shampoo for medium to thick hair. Both cleanse mildly and therefore remove clinging residue more slowly than a sulfate. To balance that, the Purifying Vinegar Shampoo replaces a normal wash every one to two weeks and takes styling and conditioning residue with it; skip it if your scalp is dry or irritated. Choosing the right MONAT shampoo comes down mainly to your hair thickness and how quickly your roots get oily again.
Quick questions
Does sulfate-free shampoo lather less?
Yes, it usually lathers less. The lather tells you little about how thoroughly it cleanses, though. If the first round barely foams, wash a second time with half the amount; on a scalp that has already been cleansed once, it usually lathers better.
Does hair get used to silicones?
No. The lengths of your hair have no metabolism and can't get used to anything. What feels rough after you stop is the surface of your lengths without a film, and damaged ends show more then.
Do I need a transition phase when I switch to silicone-free care?
No. One or two washes with a clarifying shampoo remove the old film. If your lengths feel straw-like afterwards, apply your conditioner more generously to the ends instead of waiting weeks for your hair to adjust.
Is silicone-free shampoo better?
For most hair it makes little difference. A shampoo usually leaves less silicone in your hair than a conditioner that sits on your lengths. A silicone-free shampoo pays off mainly for fine hair that quickly falls flat, or if you already use a silicone conditioner.
Are silicones in heat protectant a good idea?
Yes. They reduce friction, so straighteners and round brushes glide through your strands more easily and you go over the same section less often. How much heat protectant for your hair you apply and which temperature you choose matter more than the exact formula.
Are sulfates carcinogenic?
No. Neither SLS nor SLES is classed as carcinogenic. With SLES, the debate is about contamination with 1,4-dioxane, which can form during manufacture; it is banned as an ingredient in the EU, and technically unavoidable traces must be safe for health.
How strong your shampoo can be and how much conditioning your lengths can take depend on your scalp and your hair texture, and the free hair analysis asks about both separately.