What is in them
Eight ingredient classes, and what each one costs you
Nothing here is a proprietary complex with a trademark on it. Every product page carries the complete ingredient list in descending order; this page is the shorter version — what each class of ingredient is for, roughly what it adds to the weight number, and which products carry it.
Bond Builders
Typical weight 0–1Maleic acid and a low-weight amino complex. Used after bleach, colour or heat to improve how damaged hair looks and holds together. Rinses clean, so it adds almost nothing to the strand.
Heat Protection
Typical weight 1–2Film-forming polymers rated to 450°F. They sit on the outside of the strand and take the heat instead of it. The only ingredient class here you should not skip if you use a hot tool.
Silicone-Free Smoothing
Typical weight 2–3Plant-derived esters that lie flat on the cuticle without the build-up dimethicone leaves. Less mirror-shine than a silicone, and it washes out with an ordinary shampoo.
Squalane & Light Oils
Typical weight 2–4Olive-derived squalane, camellia and grapeseed. The lightest oils there are, which is why they are the only ones we will put near fine hair.
Hydrolysed Protein
Typical weight 1–2Wheat and rice proteins cut small enough to sit inside a damaged cuticle. Makes worn hair feel firmer. Easy to overdo — see the cautions on any product carrying it.
Humectants
Typical weight 0–2Glycerin and panthenol. Draw water into the hair and hold it there. Brilliant in normal air, temperamental in very dry or very humid air, and we say so on the page.
Scalp Exfoliants
Typical weight 0Salicylic acid at 2% in a rinse-off base. Lifts flaking and product build-up off the scalp. A cosmetic exfoliant — it is not a treatment for any scalp condition.
UV Filters for Hair
Typical weight 1Benzophenone-4 at a stated level. Slows how fast sun fades colour-treated hair. Rated for hair only — this is not a sunscreen and nothing here goes on skin.
Two things worth knowing
Protein and humectants
Protein is the one people overdo. It makes worn hair feel firmer, so when hair feels soft and stretchy the instinct is to use more. Past a certain point hair goes the other way and feels like straw. If that happens, the answer is to stop for a fortnight and use a moisture step, not to add another protein product. Every product carrying protein says so in its cautions block.
Humectants depend on the air. Glycerin and panthenol pull water into the hair, which works beautifully in ordinary air and badly at both extremes. In very dry winter air a humectant can leave hair rougher rather than softer. If your routine stops working when the weather turns, this is usually the reason, and pausing the humectant products for a few weeks is the test.