Hoconnor asks…I’ve always heard that hair grows faster in the summer. Is this true? Why? And if so, is there a way to recreate the summer benefit in the winter (such as with the addition of humidifiers, heat lamps, diet changes?)
The Right Brain responds:
We’ve said this before and we mean it: the members of the Beauty Brains Forum are awesome! After Hoconnor posted this question, SarahF and Lelaleia did some research and found several interesting references. Even though Left Brain admitted to being stumped on this one, these additional resources made us think. That’s the beauty of true science – we’re always glad to reconsider our positions when new data comes in. You can read the entire discussion in the original Forum post, but we’ll recap the highlights here.
Summer time tresses
1. Seasonal Changes in Human Hair Growth
“… The rate of growth of the beard was lowest in January and February and increased steadily from March to July to reach a peak about 60% above the winter level. The rate of growth of thigh hair showed a similar pattern though with less pronounced differences.”
2. Seasonal Variation in Trichogram in Chilean Subjects
“During summer the percentage of telogen increases and the percentage of anagen decreases. This study confirms the presence of seasonal variations in normal trichogram.”
3. Seasonality of Hair Shedding in Healthy Women
“These results confirm the findings of former authors who have indicated seasonal changes in human hair growth, though this is the first study performed systematically in a representative number of women.”
It looks like there is reasonable evidence that hair grows faster in the summer. What an interesting and surprising finding! Isn’t science wonderful?
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Three cheers for research. This is why a scientific, or as I like to call it “curiously skeptical” approach to life (and not just beauty shopping) is beneficial. You can be intrigued by an idea or product, but until you see studies that support it, you are taking a risk that is just not worth it. And even when you do see studies, more need to be done. I, well known cosmetic addict, have saved a LOT of money ever since I started to learn about ingredients, hair and skin structure and how cosmetic products are formulated. Not all of us have the time or patience to painstakingly research everything we may want to buy, but that’s why the Beauty Brains are here.
It’s very interesting – it made me think of a few things that I remember from my college days.
Melatonin is tied very closely to the amount of light exposure a subject gets – it increases at night when there is low light, which causes sleepiness, thus melatonin sleeping pills. I beileve that I learned in college that melatonin is tied to seasonal mating as well, in animals that mate seasonally. And testosterone, also a player in the reproductive system, triggers hair growth. It’s interesting to think of the mechanism of an every day observation, and why we evolved to be that way. Thanks for posting!
I hadn’t noticed a change… The body is fascinating.
Of course hair grows faster in the summer you will notice that your fingernails do as well the trick is to get exposure to more sunlight if you are lucky enough to live somewhere with 365v days of strong sunlight you will not notice a difference.
Great news as it’s June and I’m growing my hair out :]
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