Seasonal hair loss typically lasts between six and eight weeks before resolving on its own. While it is common to see an increase in hair on brushes during late September, this process is generally a biological rhythm rather than a cause for alarm.
The phenomenon is linked to a cycle where hairs that entered a resting phase during the height of summer fall out in clusters after approximately 100 days. According to a long-term study by the University Hospital Zurich, which analyzed hair root data from 823 healthy women over six years, the proportion of hairs in the resting phase (telogen) peaks around July. This results in a delayed shedding period during the early autumn. A 2025 analysis in the International Journal of Dermatology confirmed this biological rhythm by noting that individuals in the Southern Hemisphere experience these symptoms during their own autumn, between March and May.
Normal Loss vs. Medical Concern
For healthy adults, losing between 70 and 100 hairs per day is considered normal, though this number may temporarily increase during seasonal shedding weeks. Because the hair follicle remains intact, it automatically begins a new growth phase after the hair falls out.
Medical consultation is recommended if the hair loss meets any of the following criteria:
- The shedding lasts longer than eight weeks.
- Daily hair loss consistently exceeds 100 hairs.
- The part in the hair becomes visibly wider.
Factors Affecting Women Over 60
For women aged 60 and older, seasonal shedding can overlap with a permanent decrease in estrogen levels. This can facilitate female pattern hair loss, the most common form of hair loss in women, which causes the hair to thin gradually at the front and on the top of the head rather than creating bald spots.
To distinguish between seasonal loss and permanent thinning, it is suggested to take a monthly photo of the dry part under consistent lighting and styling. If hair density remains stable despite increased shedding, it is likely the autumn hair loss. If the part widens, other factors may be involved.
Treatment and Management
The German Menopause Society states that hair loss by itself is not a reason to begin hormone replacement therapy. However, if such therapy is already indicated, it can be tailored to counteract the effects of male hormones. Local scalp treatments using Minoxidil, available in pharmacies in Switzerland, Germany, and Austria, may also be helpful.
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