Best Non-Toxic, Sulfate-Free Shampoo

How many sulfate-free shampoos are actually non-toxic?

We analyzed 826 of the most popular shampoos and 531 were sulfate-free. Only 27 of those, around 5%, met the Welpr Standard, compared with 31 of 826 shampoos overall, around 4%.

Going sulfate-free barely changes the odds of a shampoo meeting the Welpr Standard. It removes a family of cleansers, but it doesn't settle questions about the rest of the formula.

When we say a shampoo is “non-toxic,” we mean it meets the Welpr Standard, our precautionary consumer standard; the shampoo guide explains what that means.

Why most sulfate-free shampoos still don't meet the Welpr Standard

Of the 531 sulfate-free shampoos, 504 didn't meet the Welpr Standard. The main reasons were undisclosed blends, almost always fragrance, and potential contamination by 1,4-dioxane. Flagged ingredients were much less common.

Flagged ingredients in sulfate-free shampoo

25 of the 531 sulfate-free shampoos listed at least one ingredient flagged by the Welpr Standard; the table below shows how often each appeared, which organization identified the concern, and why it was flagged.

Transparency issues in sulfate-free shampoo

501 of the 531 sulfate-free shampoos had at least one disclosure gap or potential-contaminant flag.

Going sulfate-free doesn't remove the 1,4-dioxane question. The most common carrier of this flag was Polyquaternium-10, a conditioning ingredient. Disodium Laureth Sulfosuccinate also carried it: it's a sulfate-free cleanser, but it's still ethoxylated, like PEGs and polysorbates. See the shampoo guide's 1,4-dioxane entry.

Fragrance remains the most common disclosure gap because removing sulfate cleansers doesn't change how scent ingredients are disclosed. The undisclosed blend entry explains how we handle that gap.

How often “free from” shampoos meet the Standard

Does avoiding another ingredient change the picture? This table compares how often shampoos without each ingredient or ingredient family met the Welpr Standard.

Fragrance-free shampoos met the Standard far more often. Undisclosed fragrance is the most common reason shampoos fail, so leaving it out removes a major disclosure gap. See our fragrance-free shampoo guide for those picks.

What does sulfate-free mean?

Sulfates are cleansers that help shampoo lift oil and dirt so they rinse away, while making it lather. In shampoo, “sulfate-free” means made without sulfate surfactants such as sodium lauryl sulfate, sodium laureth sulfate, ammonium lauryl sulfate, and sodium coco-sulfate. The claim has no legal definition for cosmetics, so we read the ingredient list rather than relying on the bottle.

Sulfate-free shampoos use other cleansers instead. Common names include sodium cocoyl isethionate, sodium methyl cocoyl taurate, decyl glucoside, and cocamidopropyl betaine.

The table below shows the sulfates we found on ingredient labels and how many of the 826 shampoos contained each.

Sodium coco-sulfate was the only sulfate in any shampoo that met the Welpr Standard. It appeared in passing shampoos, including the Ethique Scalp Health and Clarifying bars. Those shampoos aren't on this page.

SLS vs. SLES in shampoo

SLS is sodium lauryl sulfate, and SLES is sodium laureth sulfate. Both are sulfate cleansers, but SLES is made through ethoxylation, which can produce 1,4-dioxane as a byproduct.

None of the SLS or SLES shampoos met the Welpr Standard. Every SLES shampoo carried an unresolved potential 1,4-dioxane flag on SLES itself. SLS itself carries no Standard finding; those shampoos failed for other reasons, mostly undisclosed blends and potential 1,4-dioxane from other ingredients. “SLS-free” or “SLES-free” doesn't mean sulfate-free, since a formula can leave out either ingredient and still contain another sulfate cleanser.

Is sulfate-free shampoo better?

Sulfate-free shampoo isn't automatically better, but it can be a useful preference. People with curly, wavy, or dry hair often choose milder cleansing to avoid removing more oil than necessary. People with color-treated hair often want to limit fading from washing, while those with a sensitive scalp often look for gentler cleansers. Sulfate-free alone doesn't tell you how mild a shampoo will be.

Some sulfate-free shampoos produce less lather, though less foam doesn't mean less cleaning. Depending on your scalp and styling products, you may still need an occasional clarifying wash for buildup. Clarifying shampoos can be sulfate-free too.

Sulfates aren't part of the Welpr Standard: a shampoo never fails just for containing one. We treat them as a preference, as the shampoo guide's sulfate surfactant entry explains. Every sulfate-free shampoo listed on this page is also paraben-free.

Best non-toxic, sulfate-free shampoo overall

Our overall pick is the highest-ranked sulfate-free shampoo that met the Welpr Standard.

Choosing the best non-toxic, sulfate-free shampoo for your hair type and need

Here are our picks for non-toxic, sulfate-free shampoo by hair type:

Best for fine hair

Fine hair can fall flat under rich oils, butters, and heavy conditioning ingredients, even in a sulfate-free formula. Look for a lightweight or volumizing shampoo that rinses clean without leaving hair coated.

Best for dry hair

Dry hair needs cleansing that leaves some of its natural oil behind. Look for a mild sulfate-free formula with moisturizing ingredients such as glycerin or plant oils, rather than a clarifying shampoo meant to remove heavier buildup.

Best for curly and wavy hair

The scalp's oils don't travel down curls as easily as they do down straight strands, so curly hair often needs more moisture, while waves need enough to stay manageable without the weight that can pull them flat. Look for a sulfate-free shampoo with mild cleansers and conditioning ingredients that leave curls and waves manageable rather than stripped. A lightweight formula is a good starting point for waves; richer formulas may suit coarse or dry waves better.

Best for frizzy hair

Dryness and a raised outer hair layer can make strands more prone to frizz in humid air. Choose a moisturizing sulfate-free shampoo that cleans without leaving hair rough, and follow it with a conditioner.

Best for men

Choose a sulfate-free shampoo for your hair and scalp rather than the word “men” on the bottle. For short hair with oily roots, a lightweight formula that cleans thoroughly is often a better fit than a rich moisturizing shampoo.

Best for oily hair

An oily scalp still needs enough cleansing to remove excess sebum. Look for a clarifying formula and avoid heavy conditioning ingredients if they leave your roots looking greasy.

Best for sensitive scalp

A fragrance-free sulfate-free formula is a useful starting point, especially if you know you react to scent ingredients; the shampoo guide covers fragrance allergens in more detail.

Best for locs

Locs need a shampoo that reaches the scalp and rinses out thoroughly without leaving residue. Look for a clean-rinsing sulfate-free formula, and avoid heavy oils or conditioning ingredients if they leave buildup inside your locs.

Types of non-toxic, sulfate-free shampoo

We cover sulfate-free shampoo bars and liquid shampoo. The format alone doesn't tell you which cleansers a shampoo contains.

Non-toxic, sulfate-free liquid shampoo

Most sulfate-free shampoos are liquid.

Non-toxic, sulfate-free shampoo bars

Soap-based shampoo bars use soap rather than sulfate cleansers. Syndet bars vary: some use sodium cocoyl isethionate, which isn't a sulfate, while others use sodium coco-sulfate, which is.

The cleanser base also changes how a bar behaves on your hair and in hard water. See the shampoo guide's soap-based vs. syndet bar comparison for help choosing between them.