Ever noticed that you seem to lose more hair between August and October? If you have, you’re not the only one - lots of people say the same. We look into the science behind what could explain this phenomenon, and whether there’s any truth to it.
What research says about seasonal shedding
The earliest study found there might be a seasonality to hair growth cycles, by studying hair growth in 14 men for 18 months. They found that the number of hair follicles in the growth phase, known as ‘anagen’, peaked in March before steadily falling to its lowest point in September, meaning that hair growth was at its highest in March but lowest in September. Shedding peaked in August and September, where the average number of hairs lost peaked at about 60 hairs per day, which was more than double hairs lost the winter before. So, although the study is rather outdated and the sample size was very small, the evidence suggests that there might be some truth to the feeling that you lose more hair in August and September.
A more robust 2009 study reached a similar conclusion when studying hair growth patterns in 823 women over a period of 6 years. In this research, they found that the number of hair follicles in the ‘telogen’ phase, which is the shedding phase, peaked in July. A peak in telogen in July is consistent with more shedding in August to September, because the telogen phase typically lasts about two to three months. What’s happening is the follicle has transitioned out of anagen, so the hair stops growing and rests for a while before a new hair, growing beneath the surface of the skin, finally pushes the old hair out.
A handful of other small studies also came to similar findings. For instance, a study in France of 10 people found that the percentage of telogen hairs were highest between August and October, and lowest in the winter months between December and February. Similarly, a Chinese study of 41 men and women found the highest proportion of telogen hairs in September, and lowest in January.
So, as you can probably tell, seasonal shedding hasn’t been studied extensively, and the evidence is mostly based on very small groups. Still, the research seems to point to validating the sense lots of people feel that they shed the most hair in late summer and autumn.
Noticing more shedding than usual?
If you’re noticing more shedding than usual, you might be wondering what’s causing it and what you can do about it. You might be tempted to put it down to seasonal shedding, but if you’re losing significantly more hair than you’re used to or starting to notice your hair looks or feels thinner, there’s probably another factor at play.
While research could explain a small increase in hair shedding around the autumn months, it doesn’t explain noticeably thinner hair. It’s normal to shed up to 100 hairs a day as part of a healthy hair growth cycle, and a slight variance in the ratio of anagen:telogen hairs throughout the year can explain small peaks and troughs in shedding. But hair loss is a different story. It happens when the proportion of telogen hairs increases and anagen falls, so less hair is actively growing and more are being lost, for longer than just a few weeks.
Countless factors can influence the ration of anagen:telogen and increase hair shedding, like stress, certain medications or health conditions, age and poor diet are all known to have an impact on the hair growth cycle. The most common explanation for hair loss in men is genetic, though.
Androgenetic alopecia, more commonly known as male pattern baldness, is the most common form of hair loss in men. This progressive form of hair loss can start at any age after puberty and will gradually get worse unless treated. If hair loss is bothering you and you’d like to do something about it, it’s best to take action sooner rather than later.
You can take our free online consultation for personalised recommendations of a treatment plan to suit your stage of hair loss.
All of our blog articles are reviewed by our Medical Director before publication.
