Hair Loss & The Thyroid: What's Really Going On?
Hair loss can be a distressing experience, especially when you're not sure what's causing it. If you're noticing more strands in your brush or thinning patches that weren't there before, your thyroid might be playing a role. But it’s not always the only culprit. Let’s break down the connection between hair loss and the thyroid, explore other possible causes, and—most importantly—what you can do about it.
The Thyroid-Hair Loss Connection
Your thyroid is a small but mighty gland responsible for regulating metabolism, energy production, and even hair growth. When thyroid hormones are imbalanced—whether due to hypothyroidism, hyperthyroidism, or Hashimoto’s disease —hair growth cycles can be disrupted, leading to increased shedding or thinning.
How Thyroid Dysfunction Affects Hair
Slow Growth & Increased Shedding: Low thyroid hormone levels (hypothyroidism) can slow down the hair growth cycle, leading to excessive shedding and a failure to regrow hair at a normal rate.
Diffuse Thinning: Rather than developing bald spots, thyroid-related hair loss often presents as overall thinning across the scalp.
Eyebrow Thinning: A telltale sign of hypothyroidism is the loss of the outer third of the eyebrows.
Other Common Causes of Hair Loss
While thyroid health is a major factor, other issues can contribute to hair thinning, including:
1. Nutrient Deficiencies
Your hair follicles require the right nutrients to function properly. Deficiencies in the following can lead to hair loss:
Iron – Low ferritin (stored iron) levels are strongly linked to excessive shedding.
Zinc – Plays a key role in hair follicle repair and growth.
Vitamin D – Essential for stimulating hair follicles.
B Vitamins (especially Biotin & B12) – Support healthy hair structure and regrowth.
Protein – Hair is primarily made of keratin, a protein that needs adequate dietary intake to thrive.
2. Stress & Cortisol Imbalance
Chronic stress can lead to an increase in cortisol, which may trigger telogen effluvium—a condition where hair prematurely shifts into the shedding phase. Stress also affects thyroid function, compounding the issue.
3. Postpartum & Hormonal Changes
Many women experience increased hair shedding postpartum due to shifts in estrogen and progesterone. Similarly, conditions like PCOS can contribute to hair thinning, especially along the scalp.
4. Gut Health & Inflammation
A poorly functioning gut can lead to nutrient malabsorption, autoimmune flare-ups (like Hashimoto’s), and inflammation—all of which can impact hair growth.
What You Can Do to Support Hair Growth
If you suspect your thyroid or other factors are causing hair loss, here are actionable steps to take:
1. Get Your Thyroid Checked
Standard thyroid tests often miss suboptimal function. Ensure you’re testing TSH, Free T3, Free T4, Reverse T3, and thyroid antibodies (TPO & TGAb) to get the full picture.
2. Optimise Your Diet
Increase protein intake (aim for 25-30g per meal)
Incorporate iron-rich foods (grass-fed meat, eggs, leafy greens)
Boost zinc & B vitamins (seafood, nuts, seeds, organ meats)
Consume healthy fats (avocados, olive oil, salmon) for hormone support
3. Support Your Gut
Add fermented foods like sauerkraut and kefir
Take a high-quality probiotic
Reduce inflammatory foods (gluten, dairy, processed sugar)
4. Manage Stress & Sleep
Prioritise 7-9 hours of quality sleep
Practice stress-reducing techniques like breathwork, meditation, or walking
Consider adaptogenic herbs like ashwagandha for cortisol balance
5. Consider Supplementation
While food should always be your first approach, supplements like iron, zinc, vitamin D, omega-3s, and biotin can support hair regrowth if deficiencies are present. Always test before supplementing!
Hair loss isn’t just about vanity—it’s a signal from your body that something deeper is at play. Whether it’s thyroid dysfunction, nutrient deficiencies, or chronic stress, getting to the root cause is key. If you’re experiencing ongoing hair loss and aren’t sure why, a holistic assessment of your thyroid, diet, gut, and overall lifestyle could be the missing link.
Need help uncovering what’s behind your hair loss? Book a consultation today and let’s get to the root cause together.