A common belief that has been passed down generation to generation is that cutting hair actually encourages hair growth. I myself believed this to be true but found myself wondering if this wasn’t just another old wives’ tale that I was tricked into placing unwitting faith into something so silly. Time and time again, I find that I’ve been taught and indoctrinated to believe in things that turn out to be false. [INSERT DERIDING COMMENT ABOUT RELIGION HERE] And so I thought I’d do a little digging to get to the root of all this.
Starting off without looking up any sources, it conceptually made sense to me. We prune bushes for the good of it growing, right? So why wouldn’t it be similar for hair? And the second justification for why hair might grow faster would be because you are reducing the weight put on the follicles which would then, I reasoned, allow the follicles to push more hair out, encouraging production.
But I’m no biologist nor physician, and so that is where my train of thought paused until I could gather more information. I assume plant biology is different from human biology since I breathe in oxygen and don’t usually jizz out eggs that fly around in the air and up people’s noses, so the pruning analogy might not be valid. Hair also consists mainly of dead cells, yet another flaw. The physics viewpoint is tenuous at best. And so, to the internet I delved.
According to the Huffington Post  and a butt-load of other such sites, no, cutting hair does not do anything for hair growth. It gets rid of things such as split ends or weaknesses in the hair that would result in it breaking and thus partially staying shorter, but the actual rate your hair grows does not change due to the trim. Which, if you think about it, is basically only one aspect of pruning bushes (again, not a biologist). So what does affect the rate of growth? Anything?
Before I go any further, I should probably mention some of the basics about hair growth. You can check out WebMD’s article about the “science” of hair . Here, you can find information about how hair grows. Hair grows in cycles which consists of a growing period (anagen), a resting period (telogen), and a transitional phase between the two (catagen). The anagen phase lasts for about 2 to 6 years, and the catagen phase lasts for 2 to 3 weeks. The telogen period lasts for about 100 days and is when the hair stops growing and falls out, about 25 to 100 resting hairs a day. There are also three different types of hair: Lanugo (fetus hair), vellus (soft, unpigmented hair), and terminal (long, thick, and pigmented) . Here, I’m only talking about the terminal hair that can be found on the scalp. And with that, I’m moving on.
It’s really easy to notice a difference in the hair growth rate in animals; many animals have seasonal coats, thicker for winter and then we all get to enjoy the change of coats as they shed all over the place for the warmer seasons. Those of us with allergies get to doubly enjoy it. The length of the photoperiod affects animals’ follicles; the longer the day, the more at rest the follicles are and thus the shorter or thinner the hair , at least with some animals such as the cashmere goat.
Could we be affected similarly to the seasons? I didn’t look this up directly, but my answer based on the material I found is that no, our hair won’t grow more during the colder seasons, at least not significantly. And here is why I think this: we don’t shed. Not in the same sense, anyway. We don’t lose hair on an annually or semi-annually basis; instead, we lose it daily after our hair goes into the telogen phase, which 6 to 8% of our hair is at any given time . We also have different hair types (vellus and terminal, as mentioned earlier), and our hair has different properties than most animals’.
That said, there are other trends that occur during summer that could have more impact, though still imperceptively. Hair is made up of proteins, so it stands to reason that if you have a change in diet that vastly increases or reduces your protein intake, your hair growth will be affected, which WebMD also mentions . Other substances that you consume will also affect your hair growth. From what I’ve found, your diet is the biggest thing that you can control that contributes the most to your hair health and growth. Well, besides hormones, but I’ll touch on that later.
However, the same woman interviewed for the Huffington Post’s trim myth article was interviewed for another article two months later on this subject . I know, two Huffington Post (and two WebMD) references in one article. Ugh. But the appeal to authority is strong with this one! Their trichologist interviewee mentions in this article that whatever changes in our diet that comes of typical summer trends is minimal and probably not even noticeable, in essence. Whether or not this expert meant the same about the effects of diet minimally contributing to one’s hair is hard to discern from the short article. Perhaps she meant that compared to your genetics, any other change will likely not affect your hair in any significant manner. Or perhaps she meant just eating a lot of fruit compared to winter does not make a noticeable difference.
But what about drugs? The one drug most of us take, in many cases daily, is caffeine. Those of us concerned about growing hair can relax, though, because according to this study , caffeine actually helps hair shafts elongate and prolongs the anagen phase, resulting in more growth. Steroids would have a significant impact, however, as they typically contain hormones. See  (PO. . . had to) for speculation on how androgen could affect hair growth.
There are many other factors that contribute to the health and growth of your hair. Here’s a questionably reliable list of things that might aid or hinder you in your path to righteously awesome long, lovely locks . This last reference is unfortunately the least reliable as it does not have the author’s name nor references the author might have pulled information from, so read with the realization that this person could be making up whatever they wished and just feeding it to you as absolute truth. We wouldn’t want any more myths going around now, would we?
Here’s the skinny of it: trimming your hair does not affect the growing rate which is mainly determined by your genes. You can affect your hair’s health and growth in small ways, through your diet mostly, but for the most part, your hair’s growth will not change significantly without the use of hormones, intentionally or not.
EDIT: I should have mentioned this before, but perhaps the reason we might think a hair cut results in quicker growth is due to perception. The percentage growth is easier to witness, and so when we take a look at, say, 1 inch length hair, when it grows 1 more inch, that’s 100% growth. But if we look at 10 inches of hair, 1 inch growth is only 10% growth; it’s far less noticeable. Perception is a funny thing!
Fare thee well, and thanks for reading!
 The Huffington Post, 2012, “Hair Growth Tips: Do Regular Trims Really Make It Grow Faster?” Huff. Post,
 WebMD, 2010, “Hair Loss: The Science of Hair,” WebMD,
 Alwaleedi, S., 2015, “The Involvement of Androgens in Human Hair Growth,” Amer. J. of Biomed. Sciences, 7(2), pp. 105-124.
 Lin, B., Gao, F., Guo, J., Wu, D., Hao, B., Li, Y., and Zhao, C., 2016, “A Microarray-Based Analysis Reveals that a Short Photoperiod Promotes Hair Growth in the Arbas Cashmere Goat,” PLoS ONE, 11(1), doi:10.1371/journal.pone.0147124B
 Saling, J. and Martin, L., 2011, “Eat Right for Your Hair Type,” WebMD,
 The Huffington Post, 2012, “Does Hair Grow Faster in the Summer? A Pro Gives us the Real Answer,” Huff. Post.,
 Fischer, T., Herczeg-Lisztes, E., Funk, W., Zilikens, D., Biro, T., and Paus, R., 2014, “Differential Effects of Caffeine on Hair Shaft Elongation, Matrix and Outer Root Sheath Keratinocyte Proliferation, and Transforming Growth Factor-Beta2/Insulin-Like Growth Factor-1-Mediated Regulation of the Hair Cycle in Male and Female Human Hair Follicles in Vitro,” Brit. J. of Derm., 171(5), pp. 1031-1043.
 Author, G., “Factors Affecting Hair Growth,”
Picture from unsplash.com‘s Hannah Morgan