Do you seem to lose more hair in late summer and early autumn, roughly between August and October? Lots of people say the same. We’ve looked at the research to see whether there’s anything behind it.
What the research says
One of the earliest studies, from 1991, followed 14 men over 18 months to see whether hair growth changes through the year. The share of follicles in the growth phase, known as ‘anagen’, was highest in March. It then dropped steadily to its lowest point in September, so hair growth was strongest in spring and weakest in early autumn. Shedding peaked in August and September at about 60 hairs a day, more than double the amount lost the winter before. The study is old and the sample was tiny, but it suggests there may be something to the feeling that you lose more hair at this time of year.
A larger study published in 2009 came to a similar conclusion. It looked at hair growth patterns in 823 women over six years. The proportion of follicles in the ‘telogen’, or resting, phase was highest in July. That lines up with more shedding in August and September, because telogen usually lasts around two to three months. Once a follicle leaves anagen, the hair stops growing and sits in place for a while. Eventually a new hair growing underneath pushes the old one out.
A few other small studies point the same way. A French study of 10 people found the most telogen hairs between August and October and the fewest between December and February. A Chinese study of 41 men and women found telogen hairs peaked in September and were lowest in January.
Seasonal shedding hasn’t been studied in depth, and most of the evidence comes from small groups. Still, the findings so far back up what many people notice: you shed more hair in late summer and autumn.
Shedding more than usual?
If you’re losing more hair than normal, you’ll probably want to know why and what you can do about it. It’s tempting to blame the time of year. But if you’re shedding a lot more than you’re used to, or your hair is starting to look or feel thinner, something else is probably going on.
Seasonal changes might explain a small rise in shedding during autumn, but they don’t explain visibly thinner hair. Losing up to 100 hairs a day is a normal part of the hair growth cycle. Small shifts in the balance of anagen and telogen hairs through the year can cause minor ups and downs in shedding. Hair loss is different. It happens when more follicles move into telogen and fewer stay in anagen for longer than a few weeks, so less hair is growing and more is falling out.
Many things can upset this balance and increase shedding, including stress, some medications and health conditions, age and a poor diet. In men, though, the most common cause is genetic.
Androgenetic alopecia, better known as male pattern baldness, is the most common type of hair loss in men. It can start at any age after puberty and tends to get worse over time without treatment. If your hair loss is bothering you, it’s worth acting sooner rather than later.
Take our free online consultation to get a personalised treatment plan for your stage of hair loss.
All of our blog articles are reviewed by our Medical Director before publication.
