Reading an ingredient list like a trichologist

The back of the bottle is the only part of the packaging nobody designs to persuade you. It is a list, in a small font, in an order that means something — and once you can read it, most of the front becomes optional.

You do not need a chemistry degree for this. You need three habits: read the order, notice where the water sits, and learn a handful of names that tell you what a formula is really built to do.

The order is the story

Ingredients are listed by how much of them is in the bottle, from most to least, until the amounts get small — below that point, the order stops meaning much. So the first few entries describe the formula. Everything after them is nuance.

If water, usually listed as aqua, sits at the top of something sold on the strength of a botanical active, you have learned something useful. The plant is in there. It is just not what you are mostly buying.

The front of the bottle tells you what it wants to be. The back tells you what it is.

Names worth recognising

The quiet workers

Plant oils and butters appear under their botanical names — the Latin binomial, often followed by the part of the plant used. Humectants such as glycerin hold water where the skin wants it. Neither is exotic, and neither photographs well, which is probably why they rarely make it to the front.

The ones doing something else

Sulphates clean briskly and can leave the scalp feeling stripped. Silicones coat the hair so it feels smoother straight away, which is a texture rather than a condition. Denatured alcohol high on a list makes a formula feel light and dry fast. None of these are villains. But if they sit above the active you were sold on, the formula has told you its priorities.

Fragrance deserves its own line, because that single word can legitimately stand in for a long list of components. If your scalp is easily upset, it is the first thing worth doing without.

Two questions, ten seconds

What is this mostly made of, and does the ingredient in the product's name appear anywhere near the top? Ask those two things in the aisle and you will put more bottles back on the shelf than any review ever persuaded you to.

Then check the list against your own history. If a product has upset your scalp before, read the label of the one that did and the one that did not, and look for what changed. Your own experience is the only ingredient list written specifically for you.