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I heard this recently from a friend who claims every hair stylist they've ever spoken to tells them this. After some searching I've found several articles claiming it and several more claiming it's nonsense, but I didn't find any studies. So the question is, does getting regular trimmings (where a "trim" involves cutting off a very small amount of hair, say less than an inch) once every month or so have any observable effect on the growth rate of your hair? If so, how much? And if not, what is the origin of this idea?

Ideally I'm looking for studies that directly compared hair growth between people who got regular controlled trimmings and people who didn't.


A note about the question marked as duplicate: that question is explicitly about hair on the body other than the head, whereas I'm asking specifically about hair only on the head. I don't think any of the answers for that question apply here.

Sourced articles claiming that regular light trimmings to reduce split ends promotes hair growth:

Style Craze

Split ends are one of the major reasons which inhibit hair growth. If your hair is dry and damaged, then you are bound to have split ends. Trim your hair every 3 months to get rid of split ends and encourage hair growth. Remember – never prick your split ends as it would further aggravate your problem.

Daily Makeover

You will most likely only need to cut 1/2 an inch at each hair appointment, but if this tip seems counter-productive to your goal, then remember this fact from Danielle Bucco-Regazzi, Farouk Systems Creative Artist, “Healthy hair grows faster than dead hair!”

Refinery 29

Being in the beauty industry for more than ten years, I frequently speak with women with long hair who never want to get cuts to keep their length in tact. It’s a complete myth. Letting your hair grow out without ever getting it cut will deter your hair from growing at its optimal rate. All women should get cuts every six to eight weeks to promote healthy hair: The two-month trim routine will benefit your hair health and promote growth by keeping the ends nice and fresh. And, if you suffer from breakage, the split will only climb further up the shaft until it's cut.

6

The hair doesn't know, that it's been cut. Means that the hair grows as long as the anagen period allows. It grows continuously before it eventually stops, no matter how often you cut it.

The maximum terminal hair length depends on the length of the anagen (period of hair growth) for the individual. Waist-length hair or longer is only possible to reach for people with long anagen. The anagen lasts between 2 and 7 years, for some individuals even longer, and follows by shorter catagen (transition) and telogen (resting) periods. Between 85% and 90% of the hair strands are in anagen at any given time.[citation needed] The fibroblast growth factor 5 (FGF5) gene affects the hair cycle in mammals including humans; blocking FGF5 in the human scalp (by applying a herbal extract that blocked FGF5) extends the hair cycle, resulting in less hair fall and increased hair growth. Source

So, basically

The only thing that affects how long your hair is and how fast it grows is the hair itself and your genetics.

Source

And the nutrients and vitamins that you get with food and environment

  • 1
    How about nose hair, pubic hair, hair fromother parts of the body? Are they the same? – Cary Bondoc Apr 13 '16 at 2:39
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    Do you have a reference for your last line? It seems out of place. This answer neglects any consideration of split ends (which was always the reason given to me). – Oddthinking Apr 13 '16 at 3:02
  • I would prefer it if you would link to primary sources and not directly to Wikipedia. The sources to answer this question should include scientific papers that provide empiric evdience for the claims. – Christian Apr 13 '16 at 11:18
  • @Odd That's the difference between "cut" and "manicured". – fredsbend Apr 13 '16 at 14:53
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    @fredsbend: Sorry, I don't follow. Hair vs nails? – Oddthinking Apr 13 '16 at 23:52

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protected by George Chalhoub Oct 14 '15 at 10:14

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