Seasonal Hair SheddingQ: Is there something like seasonal hair shedding? Do we lose more hair in spring and summer?
A: This is an area that is currently being studied and unfortunately doesn't yet off a LOT in the way of solid evidence.
We all know that each individual's hair growth cycle is independent to him or her. The growth cycle is governed by the body's hormone levels and genetic datum. The hormone levels are usually the variant factor in the cycles, and this is the area that is being theorized on and studied.
There is some suggestive studies that show that the seasons can have an effect on the growth cycle of the hair because of the effect seasons have on hormone levels in the body. One study (an experimental study) suggests that reducing the exposure sunlight during the summer might prevent or reduce hair shedding by modifying the melatonin secretion rate from the pineal gland, which affects the hormones and their receptors in the skin of the scalp.
There IS evidence that fluctuation in hair growth and shedding due to seasonal variance is a real situation, and it is normal. The way the fluctuation manifests is usually dependent on the individual's genetics - some have an increase in growth during spring and winter, while other increase loss in those months.
But the bottom line at this stage of studies is that the seasonal variations are not really of much concern in the scheme of things when it comes to hair loss.
The hair growth cycles
The effects of the weather on your hair
What makes hair break more in the fall and winter?