'Sulfate-Free' Is on Nineteen of Our Products. The Two That Actually Contain One Say Nothing At All.

Nineteen of the fifty-six products we sell carry a sulfate-free claim. One of them is a foot cream. One is a nose pack. One is a leave-in hair oil, and one is an ampoule.

None of those four product types has ever routinely contained a sulfate. You would not put sodium laureth sulfate in a foot cream any more than you would put it in a moisturiser, because it has no job there.

Meanwhile two products in this catalogue do contain sulfate surfactants, and neither of them says a word about it.

Nineteen claims, three spellings, two actual sulfates

The claim comes out of our data in three forms: Sulfate-free on seventeen products, SLES-free on two, and SLS-free on one. Our foot cream carries both Sulfate-free and SLES-free, which is belt and braces on a product with no cleansing function at all.

Search the 1,920 ingredient rows for an actual sulfate surfactant and you get four hits across two products. The GDS hair dye shampoo has both sodium laureth sulfate and sodium lauryl sulfate, and the Levero colouring shampoo has TEA-lauryl sulfate. We grade all of them mid.

Those two products score 8.6 and 8.5, which puts them near the bottom of our catalogue for other reasons entirely. Neither makes any claim about sulfates in either direction. The honest thing about them is that they are hair dyes pretending to be shampoos, and the surfactant is the least of it.

Why SLS became the benchmark in the first place

Sodium lauryl sulfate is not just an irritating surfactant. It is the irritating surfactant, in a specific and technical sense: dermatologists use it as the positive control when they need to know whether a patch test reaction is allergic or merely irritant. Put SLS on a patch, get a reaction, and you have calibrated that person's skin.

That is a strange origin story for a marketing claim. SLS is famous for irritating skin because the profession picked it to irritate skin on purpose, reproducibly, in order to measure other things against it.

A recent paper revisits the limits of that practice, which is a useful corrective. Something can be a reliable laboratory irritant at 0.5% under occlusion for 24 hours and still be a perfectly ordinary ingredient at 1% in a shampoo you rinse off in ninety seconds. Occlusion and duration do most of the work in a patch test, and neither happens in a shower.

What replaced it, and the one head-to-head we could read

Twenty-one of our products contain an alkyl polyglucoside. Decyl glucoside appears on nine rows, coco-glucoside on six, caprylyl/capryl glucoside on five, lauryl glucoside on three. These are sugar-derived non-ionic surfactants, and they are the workhorse of the sulfate-free era.

There is one study we were able to read in full that compares them directly. Löffler and Happle, in Contact Dermatitis in 2003, patch-tested sodium lauryl sulfate, sodium laureth sulfate and alkyl polyglucoside across concentrations from 0.125% to 2.0%, with exposures of 6 to 24 hours, and then measured transepidermal water loss and blood flow at 24 hours, day 7 and day 10.

The ranking held. SLS produced effects still detectable at day 10 across the concentration range. SLES was convincingly detectable only up to day 7. The alkyl polyglucoside sites showed no significant reaction even at day 3.

So the substitution is not marketing. On the one comparison we could get to, the class that replaced sulfates behaved better than either sulfate, and SLES sat in between rather than alongside SLS. That last part matters, because "sulfate-free" flattens SLS and SLES into one villain and the data does not.

Sulfate-free soap, and a sulfate-free sulfoacetate

Here is where the claim earns its scepticism. Three products in our catalogue carry it while foaming on something that is not obviously kinder.

The papasoap blemish bar is sulfate-free and built on sodium laurate, sodium myristate, sodium palmitate and sodium stearate — four fatty-acid soaps, all of which we grade mid. True soap is alkaline by definition; that is what makes it soap. Whether a pH 9 bar is gentler than a pH 5.5 sulfate cleanser is a real question and the claim does not raise it.

The CLOROPY bath fizz is sulfate-free and foams on sodium lauryl sulfoacetate. Read that name slowly. It is not sodium lauryl sulfate — different molecule, different behaviour, and the distinction is real rather than a technicality. It is also four characters away on a label that most people scan in two seconds.

And three of our sulfate-free products run on sodium C14-16 olefin sulfonate. Sulfonate, not sulfate. Again a genuinely different chemistry, and again a claim that survives on the difference between two letters.

What our screening found

The practical takeaway

Sulfate-free on anything that does not foam is decoration. Foot cream, ampoule, hair oil, sheet mask, nose pack — ignore it entirely, the same way you would ignore "gluten-free" on a bottle of water.

On something that does foam, skip the front and find the first two surfactants on the back. Names ending in glucoside are the sugar-derived class that tested best in the comparison above. Names built on cocoyl glycinate, lauroyl glutamate, cocoyl isethionate or cocoyl alaninate are the mild amino-acid and isethionate families. Names starting sodium laurate, sodium palmitate or sodium stearate mean soap, whatever the front says.

If your skin was fine with sulfates, it is fine with sulfates. The evidence says SLS is harsher than the alternatives under a patch, not that it damages everyone in a shower, and swapping a cleanser you get on with for a claim on a bottle is not an upgrade.

Where it does matter is if you wash a lot, or if the barrier is already compromised. That is the situation the irritation studies model, and it is the one where the swap is worth making. We have written about who actually needs to cleanse twice, which is the same question from the other end, and about which label claims carry weight. Our worst-graded ingredients and the method behind all of it are on the awards page.