Hair care, explained properly
36 guides on how hair actually behaves — what the tests measure, what the ingredients do, and where the evidence runs out. Start with the two-minute test that works out which part applies to you.
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Judge it air-dried, with no product in it. The shape your hair takes on its own is the one a routine has to work with.
Try it on first
Upload one photo, pick from thirty cuts, and get it back with the new hair and the same face. One free try-on — no account, no email, no card.
Hair colour try-on lives in the app, where it runs on your device and is instant.
Straight answers
The short version of each, in full, on this page. The guide behind it goes further.
Look at the ends of what you are losing. A small white bulb means the hair completed its cycle and was released — normal up to about a hundred a day, and often traceable to something that happened two to three months ago. No bulb means it snapped, which is a handling problem, not a follicle one.
Shedding or breakage?There is no correct number. Your scalp sets the floor — if it is itchy or oily by day two, you have waited too long — and your lengths set the ceiling. The idea that washing less trains your scalp to produce less oil has been tested and does not hold up.
Find your frequencyPull a shed strand gently. If it stretches a long way and stays limp, the protein structure is gone and more conditioner will make it worse. If it snaps straight away, it is dehydrated. The two look identical in a mirror and need opposite treatment.
The stretch testLower than it is. Keratin starts changing irreversibly above about 175°C, and most irons default to 200–230°C. Fine or bleached hair belongs at 150–170°C. And never on damp hair — trapped water flash-boils and blows the cuticle open from the inside.
The temperature bandsLess than the labels suggest. Sulfates clean thoroughly, which matters if your scalp is sensitive or your hair very dry, and they do not cause hair loss. Silicones cannot suffocate hair, because hair is dead — the real issue is that some of them accumulate if your shampoo is too mild to remove them.
What silicones doMostly water, not shampoo. Every time hair swells with water, dye leaves — so long hot showers cost more colour than your surfactant choice does. Heat, UV and porosity do the rest, which is why bleached hair holds vivid colour worst of all.
Making colour lastThe library
Written by the Kera team. Where the evidence is thin, the page says so — including on the treatments we would rather be able to recommend.
Wash day, by hair type — the routine for straight, wavy, curly or coily hair, and what all four have in common.
Before a routine can be right, the hair has to be read correctly. These are the measurements that matter and the tests that actually work at a bathroom sink.
9 guidesWash day is the single habit with the most leverage in a hair routine, and it is the one most often copied from someone whose scalp is nothing like yours.
6 guidesMost ingredient advice online is a brand position dressed as chemistry. These pages stick to what a molecule does on a hair fibre, and say when nobody actually knows.
4 guidesHair is dead protein. That single fact decides what is preventable, what is cosmetic, and what is simply gone — and most damage advice ignores it.
5 guidesShedding worries are mostly timing problems: the hair you lose today was decided months ago. Knowing the delay turns panic into a plan.
6 guidesA routine only works if it survives a bad week. These are the small mechanics — order of operations, friction, sleep, tracking — that decide whether it does.
Most useful
A white bulb means shedding. A tapered end means breakage. The check takes thirty seconds and it decides your entire plan.
Washing and cleansingWhy the "train your scalp to produce less oil" advice fails, and a three-week method for finding the frequency that actually suits you.
IngredientsHair that stretches and stays stretched needs protein. Hair that snaps needs moisture. Getting this backwards is the most common self-inflicted hair problem.
Understanding your hairThe float test measures whether your hair has product on it. Three better checks, and what porosity actually changes in a routine.
Damage and repairWhat happens to keratin at each temperature band, why damp hair and a hot iron is the worst combination in hair care, and where to set the dial.
Routines and habitsEnds first, upward, with slip — plus the overnight and hair-tie changes that stop most mechanical damage.
No "best shampoo" lists, no affiliate links, no paid mentions. Products appear as categories, never as a bottle to buy. We make an app; that is the whole commercial relationship, and it is visible.
"Studies show" hides more than it explains. When a claim rests on nine people in an uncontrolled study, the page says nine people, and when nobody knows, that is what we print.
Sudden shedding, patchy loss, a painful or scaling scalp — those belong to a doctor, and every guide that touches them says so rather than selling you a routine instead.
The Kera app
Everything above is general by necessity. The app is the specific version: it reads your hair from a photo or a one-minute questionnaire, turns that into a daily routine, and tracks a density score through photo check-ins so you can tell whether any of it is working.
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