His whole routine stops four inches short.

Six lines, and all six land above the skin.

None of it is a mistake. The barber every two or three weeks is the single best purchase on that list, and nothing written here is going to argue with a man who has found one he trusts. He keeps the shape, he keeps the weight right, and he does it better than anything sold in a bottle.

But the chair reaches the hair. The shower reaches the hair. The clay reaches the top inch of it. Every one of those six lines lands on fibre that finished growing weeks or months ago, and fibre does not take instruction. It is already made. What it looks like next spring was decided underneath, in skin, before any of it came out.

He already treats skin twice a day.

Forehead, cheeks, the back of the neck, the backs of the hands. Every patch of skin on him is on a schedule and has been for a decade. He was never wrong about that. He worked out early that skin reports a man’s age before anything else does, and he has been paying for it ever since.

Then the schedule stops at the hairline. Four inches of skin, the only patch on his whole body that grows something, and the one square foot that has never had anything put on it. Not out of neglect. Nobody ever sold him anything for it. The list has six lines because the aisle only ever offered him six.

Nobody pays that bill in a bad morning. It comes due in years, which has always been his own unit for this. The scalp runs on whatever it happens to have, and it has run that way since he started shaving.

What goes on the four inches.

VALEVA Golden Oil is eight botanical oils and a vitamin E. It goes on the skin under the hair rather than through the lengths, and that is most of what separates it from everything already standing on the shelf.

Jojoba goes first, because it decides whether the rest gets in. It is a wax ester rather than a fat, which makes it the closest thing in the bottle to what the skin’s own surface already makes, so the mix soaks in instead of sitting on top of it.

Rosemary and peppermint come last on the label and take the smallest share of the bottle. The peppermint gives the cool he feels for the first minute, and it produces no other sensation at all.

Castor and batana are the heavy ones. They stay for hours rather than rinsing off, which explains why it stays on the skin instead of getting washed out of it. Coconut is the one that goes into the fibre itself and slows the protein it loses. The vitamin E is not there for his head at all: it keeps the oil in the bottle from oxidising, which a formula with no water in it needs.

Olive and avocado are the two not named above. They soften and they smooth, and that is the whole of it. Eight oils and a vitamin E. That is the label, in full.

And the honest size of the claim: the condition of that skin is not the only thing deciding how hair comes in. Genetics decides. So do age, medication, and whatever else is going on in the rest of him. Skin is the part he can do something about from the outside. That claims less than the aisle does, and it holds.

Same morning, four inches lower.

A couple of drops, parted down to the skin so it actually lands there, two to three minutes worked in with the pads of the fingers, three to five times a week. Freshly washed hair works and day-old hair works, so it does not have to wait its turn behind anything else in the morning.

Nothing on that list gives up its place for it. The oil goes to the one spot none of the six was ever pointed at.

I’ve tried two other scalp oils before this one. The first made my pillowcase greasy by the second night. I quit that one fast, and I don’t make that mistake twice. This one soaks in; my pillowcase is clean by morning.

James T., 61

Five weeks in: the shine is back and the hair has a bit more body to it. I’ll take that.

Victor A., 52

The line that was blank.

Thirty millilitres, glass, a dropper. It stands on the same shelf as the other five and none of them has to move. There is a refill plan, and support runs from one address: write to it and a person takes the case and stays on it rather than handing it down a queue.