Summer hair loss: causes and treatment

Is hair loss in summer normal? While we often hear the term "seasonal hair loss" used to describe hair loss that is more pronounced in spring or autumn, we may be right to be concerned if we lose a lot of hair at any other time of year, particularly during the summer months. What exactly is the situation?

When do we lose the most hair?

In 2009, the Department of Dermatology at Zürich University Hospital in Switzerland published an unprecedented study: involving a large panel of women aged between 18 and 78 (more than 800 participants), over an observed period of 6 years, the multidisciplinary scientific team concluded that the hair loss problems is closely linked to the rhythm of the seasons. 

Source :

Also, by examining the evolution of the life cycle of hair over a long period (6 years), scientists have demonstrated 2 things:

  1. By focusing their research on hair in the telogen phase, scientists have shown that the highest concentration of hair in the telogen phase occurs in July. Remember that hair in the telogen phase no longer grows and will inevitably fall out within a maximum of 3 months. The study therefore shows that increased hair loss is "normal" from the end of each August and in September (hair in the telogen phase observed in July + 3 months maximum).
  2. The study also shows an identical but less pronounced peak at the end of winter. The number of hairs in the telogen phase at the end of winter would therefore explain the increased hair loss we experience between April and May.

How do these scientific findings explain seasonal falls? 

Scientists are working on the hypothesis that, in humans as in all other mammals, the cellular activity of our hair follicles is influenced by hormones and follows a cyclical pattern.

This is why we have retained the moulting principle in our genes: just as animals see their coats become denser as winter approaches and thinner in anticipation of the summer heat, our hair follows the same cyclical rhythm. Thus, hair in dormant phase (telogen) are at their weakest in February, keeping our skulls warm in winter! Remember that the term "alopecia" has its origins in the ancient Greek word "alopex", meaning "the fox", by analogy with the very marked seasonal loss of hair in this animal.  

In addition, other studies conducted on mixed populations (men and women) suggest that reactivity to seasonal falls is more pronounced in women than in men.

Through all these scientific studies, it appears that the more or less intense activity of hair follicles throughout the year follows a cyclical pattern based on the rhythm of the seasons. There is therefore a phenomenon of seasonal hair loss in autumn and another in spring, although the latter is less intense. 

If all else goes well, there's no need to worry: we're simply the heirs of a long evolutionary process and the result of mammals adapting to their environment! The fox loses its hair, but it grows it all back!

Why does my hair fall out in summer?

As we have seen, our mammalian genes programme the evolution of our hair in an intelligent way: more hair in winter to protect us from the cold and less hair in summer so that we suffer less from the heat!

There are also other causes.

In our latitudes, summer is often synonymous with relaxation, sunshine and lightness. 

So all the indicators should be 'green', including for our hair. But why then - for some of us and especially some of them - do we have the impression that our hair falls out more in the middle of August?  

We normally lose hair every day, 10, 20, 30 and up to 100 or more a day. So it's normal to lose hair in summer too.

Hair falls according to a natural process of cyclical renewal, with "peaks" of hair loss generally confined to the periods of seasonal change. These peaks generally do not last no more than a few weeks and are no effect on hair density eventually.

To understand why hair loss is worse than usual, you need to go back in time. That's right, a hair that falls out is a hair already programmed to fall out for 3 months. A major stress episode in April-May could lead to severe hair loss in July-August, for example.

All the causes that cause you to lose more hair than usual: medical treatment, androgenetic alopecia, deficiencies, etc. are not going to disappear in the summer as if by magic. 

Increased hair loss may be the result of seasonal hair loss that is slightly delayed: a little late for spring hair loss, which can last until June-July, and early for autumn hair loss, which can start as early as August.

In summer, our habits change, and our hair routine can be no exception: bathing in the sea, exposure to the sun, hot weather, a lighter hair routine (we "travel light"), etc. So the scalp and the hair is likely to suffer as a result.

All these factors will affect the scalp and the hair (keratin), which is why we need to think about PROTECTION :

=> hat, scarf or cap to protect the head from sunstroke

=> hair cream or balm to deeply nourish keratin. The right thing to do? Apply Clauderer Hair Cream or Healing Balm as a mask before shampooing to dry hair, applying strand by strand to ensure the nutrients are fully absorbed. Leave on for as long as you like, including overnight (or all day on the beach for a wet but well-protected effect), then rinse and shampoo as usual. Result: hair is deeply nourished, and breakage caused by dehydration is prevented. Balms and Creams can also be used as conditioners to make detangling easier. 

=> Rinse hair thoroughly after swimming in the sea or pool to avoid lime, salt or chlorine deposits. Wash with a gentle shampoo that is as natural as possible.

For fine hair that lacks bounce or very dehydrated hair such as afros, use a richer cream cleanser rather than a traditional shampoo to boost hydration.

=> Forget about blow-drying or straightening for a while and opt for a more natural hairstyle, without aggressive blow-drying.

Finally, we're looking ahead to the start of the new school year and opting for taking food supplements to cushion the possible effects of seasonal autumnal hair loss and encourage new hair growth. Choose a course of multi-vitamins including brewer's yeast, B vitamins and ferritin to prevent iron deficiency.

When should you worry about hair loss?

Before being alarmed by a large amount of hair loss, hair loss that seems unusual, we first need to agree on the meaning of "unusual hair loss".


  1. We lose hair every day, all the time, it's normal, it's the life cycle of our hair which grows for 5 to 7 years before falling out and being replaced by new hair.
  2. We are not all equal when it comes to the amount of hair lost each day.
  3. Each case is different, depending on our genetic heritage (gender, heredity), our hair routine (brushings, hairstyles and other cosmetic manipulations), our lifestyle in the broadest sense (stress, diet, etc.) and our environment (pollution). 

In short, both endogenous and exogenous factors are responsible for the amount of hair we lose each day. 

What is normal hair loss?

In fact, an individual can lose between 50 and 150 hairs a day without it being worrying at all. 

Hair growth follows a cycle in which there are 3 phases:

Anagen phase: This is the hair growth phase. On a healthy scalp, hair in the anagen phase represents 85 % to 90 % of the hair mass. In women, the anagen phase (the life of the hair in other words) lasts around 5 to 6 years; in men, it lasts 3 to 5 years.

Catagen phase: this is the stabilisation phase - the hair is still attached to its hair follicle but it no longer grows. Approximately 1 to 2 % of the hair mass is in the catagen phase. Duration: a few weeks

Telogen phase: this is the resting phase - the hair gradually detaches from the hair follicle but remains on the scalp for a fairly long period. Pushed by the new hair generated by the hair follicle (the new hair in the anagen phase), the hair in the resting phase will eventually fall out. This process naturally takes around 3 months, but hair loss in the telogen phase can be mechanically accelerated by manipulations such as brushing (too) vigorously, for example.

When is hair loss abnormal?

When the hair's vital cycle is disrupted: in this case, the 3 phases of the hair cycle accelerate and the anagen phase becomes shorter and shorter. Instead of living for 5 years, for example, the lifespan of the hair will gradually decrease. As a result, the hair follicles produce new hair faster and faster and, because the hair doesn't have time to mature, it falls out prematurely and grows back thinner and thinner. It's a vicious circle. The hair becomes progressively poorer, with a loss of hair mass. If nothing is done, the loss of hair will inevitably continue.

It's easy to see why, we can lose 50, 60 hairs a day and even 150 hairs or more on a daily basis. What counts is the ability of hair follicles to produce new hair in at least equal quantity and quality to the previous ones during each hair cycle. In other words, if I lose 60 hairs a day but 60 of the same calibre grow back, then everything's fine. If this is not the case and the quantity of hair that grows back is less than the quantity of hair that falls out, then we need to take action and look for the causes of this abnormal hair loss among several possibilities, causes that may unfortunately be interdependent.

At Centre Clauderer, thanks to the rigour of our personalised hair diagnosis, we know how to help you identify the main and secondary causes of your hair loss and, above all, we know how to enable you to strongly stimulate regrowth your hair with targeted treatments.

Jean-François Cabos

Jean-François Cabos is the creator of a unique hair care method based on the research he coordinated, which led to the publication of the book "Cheveux, Racines de Vie" with Hélène Clauderer by Robert Laffont (Collection "Réponses/ Santé").

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