Every year, around the same time, I see the same pattern in clinic — and I feel it in my own body too.
Since my teens, long before I ever trained in biochemistry or became a functional medicine practitioner, I noticed that winter was always the season when my hair felt the most vulnerable. I didn’t have the understanding for it at the time; I just knew that come November, the shedding increased, my scalp became more reactive, and everything felt a bit harder to stabilise. I would brace myself, hoping it wouldn’t be “as bad this year.”
Now, after supporting hundreds of clients through alopecia, I understand exactly why winter creates this seasonal storm — and how entirely predictable it is. Winter brings together a unique combination of low vitamin D, reduced circulation, histamine exposure, scalp barrier stress, immune activation, and disrupted sleep rhythms. Each factor on its own can influence hair growth… but winter layers them, intensifies them, and for many people with alopecia, it becomes the perfect trigger.
Here’s why winter really does make alopecia worse, and how you can gently buffer yourself against those seasonal flares, as I do now.
Vitamin D Drops
One of the clearest patterns I see in clinic is that vitamin D almost always dips in winter, especially in the UK where we’re unable to synthesise vitamin D from sunlight between October and March. Vitamin D is essential for immune regulation, inflammation control, and even the communication pathways around the hair follicle. When it falls, the immune system becomes more reactive — and the hair follicle becomes more vulnerable.
Looking back at my own experience, every winter that I didn’t supplement, the flares came. And analysing hundreds of client test results over the years, the same theme stands out: winter vitamin D deficiency is often the quiet driver behind increased shedding and patch formation.
Supporting winter hair health starts, quite simply, with keeping vitamin D at an optimal range so the immune system has the regulatory signal it needs.
Cold Weather Reduces Circulation to the Scalp
When the temperature drops, the body prioritises warming core organs and reduces blood flow to the skin. The scalp — unfortunately — is first in line. Less circulation means less oxygen, fewer nutrients, and reduced mitochondrial activity at the follicle. For clients with low ferritin, sluggish thyroid function, or mitochondrial stress, this circulatory drop can make winter shedding even more pronounced.
I often recommend gentle ways to encourage circulation — movement, warmth, massage, and red light — not as “treatments,” but as signals that the scalp is still receiving the resources it needs. Even small habits make a noticeable difference when the environment itself is working against you.
For clients who want an easy at-home option, red light therapy can be a supportive tool for winter scalp health. A brand many of my clients like is BON CHARGE, particularly because they’ve recently launched a Red Light Cap designed specifically for the scalp. It’s convenient, targeted, and can slot into a winter routine without much effort — especially helpful when circulation naturally slows.
If you’d like to explore their red light therapy range, you can use my code AUTOIMMUNITY for a discount on any BON CHARGE products, including the new cap, here.
Dry Air Damages the Scalp Barrier
Clients often assume winter shedding is purely hormonal or autoimmune, but the scalp barrier itself plays a surprisingly large role. Central heating, cold winds, low humidity, and hot showers all strip moisture from the scalp. When the barrier becomes dry, tight, or flaky, inflammation increases — and so does shedding.
I see this every year in people with eczema, psoriasis, seborrheic dermatitis, or general scalp sensitivity. The winter months amplify barrier stress, making the immune system more reactive to what would normally be benign triggers.
One of the biggest things I emphasise in clinic is that healthy barriers require healthy fats. The scalp isn’t just passively affected by winter dryness — it’s actively dependent on the right balance of essential fatty acids and phospholipids to stay resilient. Without enough high-quality fats, the barrier becomes thinner, more permeable, and far more prone to inflammation. This is why clients who increase their omega-3s and phospholipids through winter often report less itching, less flaking, and steadier hair growth.
A range I consistently recommend is BodyBio, especially their Phosphatidylcholine (PC) and Balance Oil. PC helps restore the structure and integrity of cell membranes — something that becomes even more important when cold weather is constantly challenging the skin and scalp. Their Balance Oil supports the omega-6:omega-3 ratio that underpins barrier function, inflammation modulation, and scalp hydration. For many clients, winter is the season where focusing on fats becomes absolutely non-negotiable.
If you’d like to explore these, you can use my code VJ10 for 15% off the full BodyBio range here.
Supporting the scalp barrier through winter isn’t complicated — it’s simply about giving the body the ingredients it needs, using gentler products, avoiding excessive heat, and allowing the scalp’s natural oils to do their job. These subtle shifts often result in far less micro-inflammation, which is the hidden contributor to so many seasonal flare-ups.
Histamine Exposure Rises
One of the lesser-known factors I speak about often with clients is the rise in environmental histamine during winter. As leaves fall and decompose, they release mould spores and histamine into the air. On damp days, histamine levels can be surprisingly high.
For people with alopecia areata, histamine intolerance, MCAS tendencies, eczema, or an already reactive immune system, this can create a noticeable flare. Clients frequently describe scalp burning, itching, tingling, or increased shedding after long winter walks — and they’re often relieved to learn it isn’t “in their head.” It’s physiology.
When the immune system is hyper-responsive, histamine becomes another layer of aggravation. Supporting histamine pathways, being mindful of high-exposure days, and reducing inflammatory pressure elsewhere in the body helps restore balance.
You can read more about the link between histamine and alopecia in this article, Parasites, histamine and alopecia?
Stress, Mood & Sleep Shift in Winter
Winter affects our circadian rhythm more than most people realise. Shorter daylight hours disrupt melatonin production, lower mood, and alter cortisol patterns. For people already living with autoimmune conditions, this shift can feel like the ground moving beneath their feet.
Hair follicles are exquisitely sensitive to stress hormones and nervous system signals. When sleep quality drops or cortisol becomes irregular, shedding nearly always increases.
This is something I’ve monitored closely through my own Oura Ring over the past five years, and what it has taught me — and my clients — is that it isn’t just how much sleep you get, but whether you’re achieving restorative REM and deep sleep. When the nervous system feels safer, the hair follicle follows suit. Evening routines, calming nutrients, tech boundaries, and consistent rhythms all become vital tools in winter hair stability — but woven seamlessly into daily life rather than added pressure.
You can find out five ways to improve your sleep in this FRIDAY 5 edition of The Autoimmune RESET podcasts, The Sleep Edition — 5 Ways to Support Deeper, Restorative Rest.
Seasonal Illnesses
Winter is also the season of colds, flu, and viral load — all of which can push hairs prematurely into the telogen (shedding) phase. Many people experience increased shedding six to twelve weeks after an infection, which conveniently places the worst period right in the depth of winter.
This doesn’t mean winter illness “causes” alopecia, but it can tip the immune system into a more inflamed, less regulated state. Supporting the body through illness with hydration, nutrients, and gentle metabolic support helps minimise the lagging effects that often show up weeks later as unexpected shedding.
How To Winter-Proof Your Health
When you layer all of these winter factors together — low vitamin D, reduced scalp circulation, histamine exposure, barrier dryness, disrupted sleep, viral load, cold stress — it becomes clear why winter feels like a “danger zone” for people with alopecia.
But what I’ve learned through both personal experience and clinical practice is this: Winter doesn’t have to be the season your hair fears. When you understand the drivers, you can shift from bracing yourself for shedding to actively supporting your body in the ways winter requires.
A stable winter for alopecia is built on small, intentional habits: protecting your vitamin D levels, supporting your scalp barrier, keeping circulation flowing, nourishing the immune system, being mindful of histamine exposure, and prioritising deeper rest.
These are not rigid protocols — they are gentle adjustments that meet your physiology where it is during the colder months. And when you put them in place, you create something powerful: a winter where your hair feels healthier, your body feels calmer, and the season becomes far more manageable than it’s ever been before.
I’ve used these principles myself for the past ten years, and they’ve allowed me to go through winter without the fear and instability I used to feel. My hope is that you begin to experience that same sense of steadiness — where winter no longer feels like a season you need to brace yourself for.
If winter has always been your most challenging time, you’re not alone — and with the right support, it truly can become your most stable season yet.
To help you get started, you can download my free guide, The Autoimmunity Recovery Plan, which walks you through the core foundations I use with my clients to reduce inflammation, calm the immune system, and rebuild resilience from the inside out.
Download your free copy here
VJ Hamilton, BSc, RNT
VJ Hamilton is a Registered Nutritionist (BANT) and an expert in autoimmune disease. VJ combines her knowledge from her medical science degree in Biochemistry & Immunology with Nutritional Therapy to offer a thorough and personalised approach to support her clients based on the most current scientific research. VJ runs a virtual and in-person nutritional therapy and functional medicine practice, The Autoimmunity Nutritionist, specialising in gut skin and immune health.