Value Village ／ Beauty
This answer is a draft. It stays unpublished until legal review and source verification are complete.
You look at your ends and they are split in two; short broken hairs stick out mid-length. Almost everyone has some split ends and breakage, and the advice you hear is divided between "repair them with a hair mask" and "the only answer is to cut". In Japan, the loanword "treatment" (トリートメント, torītomento) is simply the everyday name for a conditioner or hair mask, which adds to the confusion. Starting from how hair is built, we sort out what can and cannot be fixed, and how to stop making more.
| Cause | What happens | What to do |
|---|---|---|
| Friction on wet hair | Wet hair has an open cuticle and only 70–80% of its dry strength. Rubbing with a towel or brushing wet hair peels the cuticle off | Press out water, do not rub; wide-toothed comb on wet hair, from the ends; dry promptly |
| Heat | Hair protein starts to denature at around 130°C; moisture escapes rapidly and leaves hollows | Hairdryer 20 cm away, never more than 3 seconds on one spot; irons 160°C or below, 2–3 seconds per section, not every day |
| Chemical processing | Colour, bleach and perms break the cuticle and the bonds inside. A single bleach damages most of the cuticle | Do it less often (full colour once every 2–3 months), mostly root touch-ups, avoid heat and UV for a week afterwards |
| UV light | Breaks down protein and pigment | Hat, parasol, UV spray for hair |
| Brushing | Dragging a hard brush through dry hair from the roots in one go rips through tangles | Ends → middle → roots, natural-bristle or cushion brush, not many times a day |
| Friction (pillow, collar, scarf) | Rubbing during sleep; collars and scarves rubbing in winter | Silk or satin pillowcase, tie long hair loosely to sleep, do not tuck hair inside a scarf |
| Nutrition and health | Extreme dieting, iron deficiency, after childbirth | Improves with a normal diet. See a doctor about sudden changes |
[Verify] The denaturation temperature of hair protein and the loss of strength in wet hair are standard figures from hair science. Check against material from the Japan Hair Science Association and the Japan Cosmetic Industry Association.
Hair is dead cells, and a split end does not go back. A conditioner or mask improves feel and appearance and helps prevent new splits. Split ends get cut.
The hair around a split end has taken the same damage and is next in line. Trimming 1–2 cm off all the ends works better.
The longer hair stays wet, the longer it takes friction with the cuticle open. Used correctly, a hairdryer is less damaging.
Excess brushing adds friction and creates split ends. Once or twice a day, from the ends, working tangles loose.
How you dry, heat, brush and how often you colour matter far more than the shampoo. Fix the habits first.
---
https://www.jcia.org/user/public/knowledge/usage
https://www.kamiken.org/
https://www.nite.go.jp/jiko/chuikanki/
⚠️ Editorial note: the source URLs above were identified by search. Our working environment cannot reach go.jp domains, so the contents have not been checked against the text. Verify every source before publication and record who checked it and when.
What we share here are ideas and everyday practices passed down among people living in Japan, together with general information drawn from public sources. They are not official recommendations, and they are not professional instruction. Practices vary between households and regions.
This is general information. Results vary from person to person and depend on your own conditions and surroundings.
Please decide for yourself, using your own judgement, whether any of this suits your situation. We cannot accept responsibility for any damage, loss or injury arising from following this article.
Cosmetics are not medicines and are not meant to diagnose, heal or prevent any condition. If your skin reacts, stop using the product and see a dermatologist.
Tell us if this has changed
Approved contributions keep the contributor's name, shown in five languages.
Other languages：日本語 ／ 简体中文 ／ 繁體中文 ／ 한국어
Value Village is not a government body. Always confirm procedures on the official site.
Written by Value Village from public sources. Nothing here is reproduced from another site.