Yes, thyroid problems can cause hair loss and thinning, especially when hormone levels are too low (hypothyroidism) or too high (hyperthyroidism). In most cases, this shows up as diffuse thinning across the scalp rather than a single bald patch, and it often improves once your thyroid is treated and your follicles are supported.
The thyroid gland produces two key hormones, T3 and T4, that regulate energy, growth, and cell renewal throughout the body. Because hair follicles are highly sensitive to these hormones, even slight imbalances can disrupt their cycle, resulting in thinning or increased shedding.
A 2024 study confirms that one in every two people with hyperthyroidism and one in three with hypothyroidism develop measurable alopecia. So if you’re asking, “Could my thyroid be why my hair is thinning?” The science backs it.
If you’re still unsure whether your hair loss is thyroid-related or just seasonal, we’ll walk you through the causes, signs, debunk common myths, and share simple steps to regain healthier hair and if you’re noticing shedding already, you may also find our guide on how red light therapy can help you stop hair shedding helpful.
Why Does Thyroid Cause Hair Loss?
Thyroid-related hair loss mainly comes down to how hormone imbalances disrupt the hair growth cycle. Both low and high thyroid levels can push more hairs into the shedding phase at the same time.
Hypothyroidism (low thyroid hormone levels)
When your thyroid is underactive:
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Hair follicles don’t get enough stimulation.
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Cell renewal slows down, so hair grows more slowly and more weakly.
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Strands can become dry, brittle, and break easily, leading to overall thinning across the scalp.
Hyperthyroidism (excess thyroid hormone levels)
When your thyroid is overactive:
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Hair follicles are essentially overstimulated.
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The growth phase becomes shorter, so hairs don’t stay anchored as long as they should.
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More hairs shed at once, causing noticeable loss of volume and density.
In both cases, the problem isn’t just how much hair you shed in a day, it’s that too many follicles cycle out of growth at the same time, which is why you start to see visible thinning.
What does thyroid-related hair loss look like?
When people notice thinning hair, it’s not always easy to tell what’s behind it. Regular hair loss often stems from genetics, aging, or styling damage, while thyroid issues can cause hair loss in a very different way.
Here’s what hair loss related to thyroid looks like. If you want to see how consistent treatment can change density over time, take a look at our red light therapy hair growth before and after guide :
Before thyroid hair loss
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Healthy growth cycle: Hair typically grows in phases: anagen (growth phase), catagen (transition phase), and telogen (resting phase). A balanced thyroid keeps these cycles steady.
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Early warning signs: Subtle changes like increased shedding, brittle strands, or slower growth may appear before significant loss.
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Underlying causes: Shedding 50–100 hairs a day is normal and often linked to aging, stress, or genetics. Losing more than that may signal deeper issues such as hormonal imbalance, medical conditions, or nutritional deficiencies.
During thyroid hair loss
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Diffuse thinning: Unlike patchy bald spots, thyroid-related hair loss can occur as overall thinning across the scalp.
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Emotional impact: Hair loss can trigger feelings of insecurity, stress, or frustration.
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Other symptoms: Fatigue, brittle nails, dry skin, and weight changes often accompany hair loss, signaling thyroid imbalance.
After thyroid hair loss
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Treatment options: With proper thyroid management through prescribed medication, lifestyle changes, and close monitoring, hair growth often naturally resumes over time.
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Hair regrowth patterns: New hair may initially feel finer or softer, gradually thickening as the follicle stabilizes.
Unlike everyday hair shedding, thyroid-related hair loss doesn’t resolve on its own. Recognizing these signs early is the first step to protecting your hair before the loss becomes more advanced.
What Are Thyroid-Related Hair Loss Symptoms?
Thyroid-related hair loss usually shows up as diffuse thinning and changes in how your hair feels and grows, rather than a single bald spot. Here are the most common thyroid hair loss symptoms to watch for:
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Diffuse thinning on the scalp:
Hair looks less dense all over the head. Instead of round bald patches, you’ll notice a wider part, a thinner ponytail, and an overall “see-through” look.
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Excessive shedding:
You consistently see more strands than usual on your pillow, in the shower, on your clothes, or in your hairbrush. This shedding continues for weeks or months, not just a few days.
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Changes in hair texture:
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With hypothyroidism, hair may become dry, coarse, and brittle, breaking more easily.
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With hyperthyroidism, hair often feels finer, softer, and more fragile, with less body and volume.
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Loss of eyebrow and body hair:
Thinning can affect more than just your scalp. Many people notice sparse eyebrows (especially the outer third), fewer eyelashes, or reduced hair on arms and legs.
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Slow or delayed regrowth:
Hair seems to take much longer to grow back after shedding, trimming, or breakage. Baby hairs along the hairline or part may be sparse, short, or slow to appear, if you’re unsure whether you’re seeing new growth or just breakage, our article on new hair growth vs breakage can help you tell the difference.
These signs don’t confirm a thyroid problem on their own, but together they form a clear picture of possible thyroid-related hair loss and are worth discussing with your doctor.
What are some myths about thyroid-related hair loss?
No doubt hair loss can feel overwhelming. The reassuring truth is that many fears around thyroid-related hair thinning are mostly based on myths instead of facts.
Myth 1: Only women experience thyroid-related hair loss.
Men are equally affected by hormonal imbalances. In fact, studies show that 1 in every 20 men has thyroid disorders, causing hair loss in both genders.
Myth 2: Thyroid hair loss is permanent.
With proper medical treatment and supportive care, your hair can regrow. Once thyroid hormones stabilize, follicles return to their normal growth cycle, allowing hair density to improve over time.
Alongside medical management, supportive treatments such as gentle hair care practices, topical therapies, and non-invasive options like red light laser hair growth therapy can enhance recovery.
Myth 3: Hair loss stops immediately after starting thyroid medication.
While thyroid treatment begins to balance hormone levels, hair follicles need time to recover. Hence, you need to be patient. Is hair loss reversible? Yes, but it may take several months before improvement is visible.
How to Control Hair Loss Caused by Thyroid Early
The earlier you address thyroid-related hair loss, the easier it is to slow shedding and support regrowth. Here are practical steps to get in front of the problem:
1. Get tested: If you notice unusual hair loss, consult a dermatologist or specialist. Blood tests for TSH, T3, and T4 confirm whether hair loss is linked to thyroid.
2. Treat the root cause: Topical serums or shampoos won’t help if the thyroid imbalance isn’t treated. For hypothyroidism, doctors usually prescribe FDA‑approved Levothyroxine, while hyperthyroidism is managed with antithyroid drugs like Methimazole.
Note: Take medical treatment under professional guidance only.
3. Support hair health naturally: Nutrient-rich diet and gentle hair care go a long way in protecting your hair. Consult a nutritionist to include protein, iron, zinc, vitamin D, and biotin in your diet. Also, avoid harsh chemical treatments, tight hairstyles, and excessive heat styling.
4. Manage stress and lifestyle: Stress can worsen thyroid function and increase hair loss in general. Practices like yoga, meditation, and consistent sleep help regulate hormones and improve overall well-being.
5. Be patient with hair regrowth: Hair doesn’t bounce back overnight. Follicles need time to heal, and once thyroid levels stabilize, regrowth can take 6–12 months. Patience and consistency make all the difference.
How Red Light Therapy Supports Hair Regrowth in Thyroid-Related Hair Loss
When thyroid imbalance weakens hair follicles, medical treatment focuses on correcting hormone levels. Red light therapy (also called low-level laser therapy, or LLLT) can then play a supportive role by helping those stressed follicles function more normally again.
The iRESTORE laser hair growth system uses controlled red light to gently penetrate the scalp and:
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Support blood flow around the hair follicle
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Stimulate cellular activity in the hair root
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Help follicles spend more time in the growth phase and less time in prolonged rest
Over time, this can translate into:
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Reduced excessive shedding
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Thicker, stronger strands
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A healthier-looking scalp and improved hair density with consistent use
iRESTORE’s FDA-cleared red light therapy devices are non-invasive, drug-free, and pain-free, making them a convenient at-home option to pair with your doctor’s thyroid treatment plan. They don’t replace thyroid medication or medical care but they can complement your regimen by giving weakened follicles extra support while your hormones stabilize.
When to See a Doctor About Thyroid and Hair Loss
If you notice persistent hair thinning along with other thyroid-related symptoms such as fatigue, sudden weight changes, brittle nails, or dry skin, it’s time to consult a healthcare professional.
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Seek medical advice if hair loss continues for more than 3–6 months despite lifestyle changes.
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Visit a doctor immediately if hair loss is followed by sudden weight changes, mood swings, or swelling in the neck.
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Routine blood tests (TSH, T3, T4) can confirm whether thyroid imbalance is the root cause.
What Are the Do’s and Don’ts for Thyroid-Related Hair Loss?
Do’s:
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Take your thyroid medication exactly as prescribed and keep up with follow-up tests.
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Eat nutrient-rich meals with enough protein, iron, zinc, vitamin D, and healthy fats (with your doctor’s guidance).
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Use gentle hair care: mild shampoo, careful detangling, minimal heat styling.
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Manage stress and sleep with simple habits like walks, stretching, or a wind-down routine.
Don’ts:
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Don’t stop or change thyroid medication on your own.
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Don’t rely only on shampoos or oils to fix thyroid-related hair loss without treating the hormone imbalance.
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Don’t overdo harsh treatments like bleaching, frequent coloring, or tight hairstyles.
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Don’t overload on iodine or “thyroid boosters” without medical advice.
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Don’t expect overnight regrowth—thyroid hair recovery usually takes several months.
Conclusion
Hair loss from thyroid imbalance can feel overwhelming, but recovery is within reach. With the right medical care, a nourishing diet, and gentle hair treatment, your hair follicles can gradually regain strength.
That’s where iRESTORE’s red light hair growth device comes in. Working in sync with your body, it gently supports blood flow, re‑energizes follicles, and supports gradual regrowth. Just three 25‑minute sessions each week help restore balance to your scalp and encourage healthier strands. With steady use, many see hair becoming stronger and shinier over 6–12 months.
FAQs About Thyroid and Hair Loss
1. How to know if hair loss is due to thyroid?
Thyroid hair loss shows as diffuse thinning, not patches. It often comes with fatigue, mood swings, weight changes, or dry skin. If thinning occurs alongside these symptoms, a doctor-recommended thyroid test (TSH, T3, T4) is the best way to confirm.
2. Does thyroid medication cause hair loss?
Yes, but usually in the short term. Extra shedding may occur in the first few months as follicles adjust. Once thyroid levels stabilize, hair regrowth begins. Medication‑related hair loss is temporary and far less harmful than an untreated thyroid imbalance.
3. How to stop hair thinning from thyroid?
Treat the thyroid imbalance first with medical guidance. Support recovery through balanced nutrition, gentle hair care, and stress management. Together, these steps help restore hair health.
4. What home remedies and lifestyle changes help prevent thyroid-related hair loss?
Eat protein, leafy greens, nuts, and omega‑rich foods. Practice stress‑relieving exercises and scalp massage for hair growth. Avoid harsh styling and chemicals on hair. Together with thyroid treatment, these habits can help strengthen hair and help reduce shedding.
5. Can thyroid hair loss be reversed?
Yes. Once hormones stabilize, regrowth often begins within months. Full thickness may take longer, but with consistent treatment and proper nutrition, most patients regain significant hair volume over time.
Disclaimer: The iRESTORE blog is for informational purposes only and is not intended to replace professional medical advice or treatment. Please do not ignore professional guidance because of information you’ve read here. If you have concerns about your hair or skin health, we encourage you to consult a qualified healthcare professional.
