THE LABEL FILES · Conditioner
What's Actually in Your Conditioner
The preservative the EU banned from leave-on products in 2014 is still in most of these rinse-off bottles.
Conditioner is the rare category where most of what is on the label is genuinely fine. The fatty alcohols, the cationic agents that bind to your hair, and the silicones that smooth it are all well-cleared chemistry that does exactly what conditioner is supposed to do. So this teardown spends most of its time clearing things, and the rest of it on the two flags that actually matter.
What we clear, plainly
Silicones like dimethicone get blamed for everything; in reality they sit on the hair, are not absorbed, and the worst they do is build up and make hair feel heavy until you clarify-wash. That is a comfort cycle, not a health risk, and the environmental concern people raise is about a different molecule, volatile D5, not dimethicone. The cationic conditioning agents (behentrimonium, cetrimonium) are cleared by both US and EU reviewers for rinse-off use. They are quats, but equating them with the sprayed disinfectant quats that trigger asthma is a category error, different chemical, concentration, and route.
The preservative that is the real flag
The genuine issue runs through four of these five bottles: methylisothiazolinone paired with methylchloroisothiazolinone, the MCI/MI combo. It set off such a wave of contact allergy that the EU banned it from leave-on products in 2014. It is still legal in US rinse-offs, and rinse-off is not the same as zero contact. One brand, Suave, goes further and adds bronopol, a preservative that slowly releases formaldehyde. The cleanest of the set, Aussie, skips both, which proves the others do not need them.
And the one word, again
Every conditioner here, the cheap and the premium alike, lists a single 'Fragrance' or 'Parfum' that stands in for an undisclosed blend. It is the same black box that runs through every category in the Label Files. If your scalp is reactive or you just want to know what you are putting on your head daily, fragrance-free is the one label phrase that closes it. Most of the rest of the conditioner, genuinely, you can stop worrying about.
The teardowns
Pantene Pro-V Daily Moisture Renewal Conditioner →
The conditioning chemistry is fine. The preservative pair is the part worth knowing.
TRESemmé Moisture Rich Conditioner →
Heavy on the conditioning chemistry (which is fine) and heavy on the MCI/MI preservative pair (which isn't).
Herbal Essences bio:renew Coconut Milk Conditioner →
The coconut and aloe are mostly marketing position. The MCI/MI is the real ingredient story.
Suave Essentials Conditioner →
No silicones, but a preservative that slowly releases formaldehyde sets this one apart.
Aussie 3 Minute Miracle Moisture →
A rare conditioner with no MCI/MI and no formaldehyde releaser. The flag here is just fragrance.
The ingredients, graded
Editorial analysis of publicly listed labels and regulatory/peer-reviewed sources. Not medical advice. Verdicts are evidence-graded, we flag what the data flags and clear what it clears.