Why Your Hair Falls Out More in Winter

If you’ve noticed extra shedding in the shower, on your pillow, or in your brush during the winter months, you’re not imagining it. Hair loss often increases in fall and winter, and the reasons have less to do with genetics and more to do with seasonal stress on the scalp, hormones, and overall health.

Winter changes your environment in ways that quietly affect the hair growth cycle. Understanding what’s happening inside your body can help you prevent shedding — and support healthier, stronger hair.

❄️ 1. Dry Winter Air Weakens the Hair Shaft

Cold, dry air pulls moisture out of your skin and hair. Because the hair shaft loses hydration faster in low humidity, strands become:

• brittle

• frizzy

• prone to breakage

• more likely to split

This isn’t true “hair loss” from the root — but breakage can mimic shedding.

Indoor heating makes it worse by lowering humidity even more, leading to dry scalp and fragile strands.

🌬️ 2. Your Scalp Also Dries Out (A Hidden Cause of Shedding)

A dry scalp can become:

• itchy

• flaky

• inflamed

Inflammation disrupts hair follicles, pushing more strands into the telogen (shedding) phase of the cycle.
Conditions like dandruff and seborrheic dermatitis flare in winter, which accelerates shedding.

🌞 3. Lower Sunlight = Lower Vitamin D = More Hair Loss

Vitamin D plays a direct role in hair growth. In winter, sunlight exposure drops drastically, and vitamin D levels fall.

Low vitamin D is strongly linked to:

• increased shedding

• slower regrowth

• weaker hair follicles

Many people don’t realize that winter hair loss can be a simple reflection of seasonal vitamin D deficiency.

🍽️ 4. Winter Nutrition Changes (More Comfort Food, Less Protein)

Cold weather shifts appetite and habits. People tend to eat:

• fewer fruits and vegetables

• fewer protein-rich meals

• more carb-heavy or comfort foods

Hair is made of keratin — a protein — so inadequate protein quickly affects the growth cycle.

Even small nutritional shifts can trigger telogen effluvium, a temporary but noticeable shedding phase.

😴 5. Stress, Illness, and Post-Viral Shedding Are More Common in Winter

Winter brings:

• colds

• flu

• RSV

• COVID

• increased stress

• poor sleep

Any illness or major stressor can trigger hair shedding 2–3 months later.
This means March hair loss might actually come from a December flu.

Winter also increases cortisol levels due to less sunlight and more indoor time, which contributes to hair cycle disruption.

💧 6. Dehydration — One of the Most Overlooked Causes

Most people drink less water in winter.
But dehydration affects:

• scalp health

• oil production

• hair shaft strength

• follicle function

A dehydrated scalp can’t support healthy growth, and the hair becomes brittle and prone to breakage.

🔁 7. Natural Seasonal Shedding Patterns

Studies show humans shed slightly more hair in fall and winter — an evolutionary response to thicker summer growth and colder weather patterns.

Seasonal shedding is normal, but winter stressors can intensify it.