Shampoo Without Formaldehyde Releasers Like DMDM Hydantoin

A shampoo without formaldehyde releasers is one whose INCI list contains none of the preservatives that slowly give off formaldehyde in water: DMDM hydantoin, imidazolidinyl urea, diazolidinyl urea, quaternium-15, bronopol (2-bromo-2-nitropropane-1,3-diol), and sodium hydroxymethylglycinate. These names, not the word "formaldehyde," are what you will find on a label, because the releaser is the listed ingredient. Formaldehyde was the American Contact Dermatitis Society's Allergen of the Year for 2015, the US FDA lists the releasers among common cosmetic allergens, and since 2024 EU products must carry a "releases formaldehyde" warning above a low threshold. A contact allergy to formaldehyde is a medical matter: read the full INCI and patch-test with a dermatologist or allergist before relying on any product.

What a formaldehyde releaser is

Formaldehyde itself is rarely added to shampoo. What formulators use instead is a class of preservatives that are chemically bound forms of formaldehyde: in water, they slowly break down and release it in low concentrations, and that free formaldehyde is what stops bacteria and mold from growing in the bottle. DMDM hydantoin, imidazolidinyl urea, diazolidinyl urea, quaternium-15, bronopol, and sodium hydroxymethylglycinate all work this way, though they differ in how much formaldehyde they release and how quickly. They were widely adopted in the 1980s and 1990s as cheap, effective, broad-spectrum options, and DMDM hydantoin in particular became a staple of mass-market shampoos and conditioners.

The catch is that formaldehyde is a well-established contact allergen. The American Contact Dermatitis Society named it Allergen of the Year for 2015, with Pontén and Bruze noting that exposure is widespread and that the allergy is easy to miss in an individual patient, precisely because the source is hidden behind a different ingredient name. Someone sensitized to formaldehyde can react to a releaser-preserved product without ever seeing "formaldehyde" on the label, which is why patient guidance from DermNet and the FDA is to learn the releaser names and avoid them as a group.

The DMDM hydantoin lawsuits, stated carefully

Beginning in 2021, consumers in the United States filed proposed class actions against the makers of several shampoo and conditioner lines, alleging that DMDM hydantoin in those products caused hair loss, scalp irritation, and allergic reactions, and that the companies had failed to warn. The most widely reported case, Whipple v. Johnson & Johnson Consumer Inc., concerned the OGX line and was filed in June 2021; it was dismissed with prejudice on 22 March 2022, and the dismissal order gave no reasons and created no public claims process. Related federal cases against the same defendant were reported as consolidated in New Jersey and resolved by confidential settlement in the same month. Separate litigation over TRESemmé products has been reported as ongoing.

Two things are worth keeping straight. First, these complaints are allegations; no court has found that DMDM hydantoin causes hair loss, and a dismissal or a confidential settlement establishes nothing either way. Second, the allergy question is separate from the hair-loss question. Formaldehyde contact allergy is documented in the dermatology literature independently of any lawsuit, and that, not the litigation, is the reason a person with a positive patch test is told to avoid releasers. The lawsuits mainly changed the market: several brands reformulated, and "DMDM hydantoin-free" became a label claim, which makes reading the INCI more important, not less, since a reformulated product may have swapped one releaser for another.

How to spot formaldehyde releasers on a label

Preservatives appear near the end of an INCI list, so read all the way down. The table lists the names to look for, their EU status, and what each is. In the EU, a product whose total formaldehyde release exceeds 0.001% (10 ppm) must now carry the words "releases formaldehyde" on the label under Commission Regulation (EU) 2022/1181; the SCCS had concluded the old 0.05% threshold did not protect people already sensitized. That warning is helpful where it applies, but it is not universal: it does not exist on US labels, and a product just under the threshold carries no warning while still containing the releaser. The ingredient name remains the reliable signal.

What brands use instead, and what Baresel uses

Shampoos that leave the releasers out generally preserve with one of three systems: organic-acid salts (sodium benzoate and potassium sorbate, which need a mildly acidic pH to work), phenoxyethanol-based blends (often with ethylhexylglycerin), or parabens. Some also lean on isothiazolinones (MI/MCI), which solve the formaldehyde problem by introducing a different, well-documented allergen, so a label that says "formaldehyde-free" still needs reading. Baresel is one example of the organic-acid approach: its published INCI is Aqua/Water, Sodium Cocoyl Isethionate, Sodium Methyl Cocoyl Taurate, Sodium Cocoyl Glutamate, Glycerin, Panthenol, Sodium Chloride, Guar Hydroxypropyltrimonium Chloride, Citric Acid, Sodium Benzoate, Potassium Sorbate, Tocopherol, with no formaldehyde releaser and no MI/MCI. This formula is confirmed with the manufacturer; the label on the bottle matches it, and you hear first if anything ever changes. Baresel is a cosmetic, not a treatment; if formaldehyde is on your patch-test results, check this or any list against them with your dermatologist or allergist before use.