Yes, hypothyroidism can cause hair loss. Thyroid hormones help regulate many processes involved in growth and metabolism, including the normal hair growth cycle. When thyroid hormone levels are too low, hair can become dry, coarse, brittle & more likely to shed.
This can result in hypothyroidism hair loss, which often appears as diffuse thinning rather than a single bald patch. As a licensed Naturopathic Doctor and primary care healthcare provider with nearly 20 years of clinical experience, I have observed that hair loss can be particularly frustrating because it is visible, emotionally difficult & often slower to improve than other symptoms.
In my opinion, the key is to determine whether the thyroid is actually causing the hair loss, whether another factor is contributing, or whether several issues are occurring at the same time.
How does hypothyroidism affect hair?
Hair grows in cycles.
Each follicle moves through periods of:
- Growth
- Transition
- Rest
- Shedding
Thyroid hormones influence these cycles. When thyroid hormone levels become too low, more hairs may shift into the resting phase. Several months later, increased shedding can occur. This means hair loss hypothyroidism can sometimes appear after the thyroid problem has already been developing for some time.
The hair may also become:
- Dry
- Coarse
- Brittle
- Less shiny
- Slower growing
Some people also notice thinning of the outer portion of the eyebrows.
What does hypothyroid hair loss look like?
Hypothyroid hair loss is usually diffuse. That means the hair tends to thin across the scalp rather than disappearing from one clearly defined location.
A person may notice:
- More hair in the shower
- More hair on the pillow
- Increased shedding while brushing
- A thinner ponytail
- More visible scalp
- Reduced overall hair density
The pattern may look different between individuals. Thyroid hair loss female concerns may overlap with female pattern hair loss, iron deficiency, menopause, PCOS & postpartum shedding. Thyroid hair loss male concerns may overlap with male pattern baldness, which commonly causes recession at the temples or thinning at the crown. This is why the pattern of loss matters.
Can hyperthyroidism also cause hair loss?
Yes. Hyperthyroidism hair loss can also occur. When thyroid hormone levels are too high, the hair-growth cycle may also become disrupted. The result can be increased shedding and diffuse thinning. This means both an underactive and an overactive thyroid can affect hair. The phrase hair loss thyroid therefore does not automatically mean hypothyroidism. Blood testing is needed to determine whether thyroid hormone levels are too high, too low, or normal.
For a clearer understanding of thyroid-related changes, Aspire Natural Health’s thyroid testing services can help support assessment alongside your regular medical care.
Why does thyroid disease cause hair loss?
There are several possible mechanisms.
Changes in the hair growth cycle
Abnormal thyroid hormone levels can push more hairs into the resting and shedding phases.
Changes in hair texture
Hypothyroidism can reduce skin and hair hydration.
Hair may become:
- Drier
- More brittle
- More prone to breakage
Autoimmune disease
The most common cause of hypothyroidism in many populations is Hashimoto's thyroiditis. Because Hashimoto's is an autoimmune condition, someone may also have an increased risk of other autoimmune disorders, including alopecia areata. Alopecia areata typically causes clearly defined patches of hair loss rather than diffuse thinning.
Thyroid hair loss often improves after thyroid hormone levels are properly treated, but visible regrowth can take several months because hair grows slowly.
Is hair loss always caused by hypothyroidism?
No. Hair loss is extremely common and has many possible causes.
To explore other possible contributors beyond thyroid function, read our naturopathic perspective on hair loss.
These include:
- Iron deficiency
- Low ferritin
- Major illness
- Surgery
- Rapid weight loss
- Significant stress
- Pregnancy and postpartum changes
- Menopause
- PCOS
- Nutrient deficiencies
- Certain medications
- Autoimmune disease
- Genetics
- Scalp conditions
Through my education as a Naturopathic Doctor, I learned how closely thyroid function and hair growth are connected. Through clinical practice, I have also observed that attributing every case of hair loss to the thyroid can delay recognition of another cause.
Iron deficiency & thyroid hair loss
Iron deserves particular attention. Low iron stores can independently contribute to hair shedding.
Someone may therefore have both:
- Hypothyroidism
- Low ferritin or iron deficiency
This combination can make hair loss more significant.
Depending on the person's history and symptoms, testing may include:
- Complete blood count
- Ferritin
- Iron studies
Iron supplementation should generally be based on an identified need rather than taken automatically.
What about vitamin D, B12, zinc & other nutrients?
Several nutrients are important for normal hair growth.
These include:
- Iron
- Zinc
- Vitamin D
- Vitamin B12
- Folate
- Protein
This has led to widespread marketing of vitamins for thyroid hair loss. However, taking large amounts of nutrients does not necessarily make hair grow faster. If someone is deficient, correcting that deficiency can be important. If their levels are already adequate, taking more may provide little benefit and, in some cases, create problems. For example, excess zinc can contribute to copper deficiency.
Does biotin help thyroid hair loss?
Biotin is commonly marketed for hair growth. True biotin deficiency can cause hair problems, but deficiency is uncommon. More importantly, high-dose biotin supplements can interfere with certain laboratory tests, including thyroid blood tests. This can produce misleading results. If you take a high-dose biotin product, tell your healthcare provider before thyroid testing. In my opinion, this is a good example of why supplements should not be treated as automatically harmless.
Thyroid dry hair remedies
Thyroid dry hair remedies should begin with correcting the underlying thyroid problem if thyroid dysfunction is present. Hair care can also reduce breakage.
Helpful strategies may include:
- Using a gentle shampoo
- Conditioning regularly
- Avoiding excessive heat
- Limiting bleaching and harsh chemical treatments
- Avoiding very tight hairstyles
- Brushing gently
- Reducing excessive straightening or curling
These strategies improve hair handling, but they do not replace treatment of hypothyroidism.
Thyroid hair loss treatment
The primary thyroid hair loss treatment is correcting abnormal thyroid hormone levels. For hypothyroidism, this commonly involves thyroid hormone replacement such as levothyroxine. Hair recovery usually takes longer than improvements in symptoms such as energy or constipation. This is because hair follicles need time to return to a normal growth cycle. It can take several months before noticeable regrowth occurs.
Why can hair loss continue after starting thyroid medication?
This can happen for several reasons. First, hair-growth cycles are slow. A hair that entered the resting phase weeks or months earlier may still shed even after thyroid treatment has started. Second, the medication dose may still need adjustment. Third, the hair loss may have another cause.
Potential contributors include:
- Low ferritin
- Stress
- Menopause
- Recent illness
- Rapid weight loss
- Genetics
- Medication changes
There can also be temporary shedding after significant changes in thyroid hormone levels. This does not automatically mean the medication is damaging the hair.
How long does thyroid hair loss take to improve?
Hair grows slowly. Once thyroid function is properly controlled, reduced shedding may occur over several months. Visible regrowth can take longer. Someone may notice small new hairs before seeing a major change in overall density. Hair grows at approximately one centimetre per month on average, so restoring density is a gradual process. We need to understand the patient deeply to provide holistic treatment because the timeline depends on how long the thyroid dysfunction existed, whether another cause is present & the individual's natural hair cycle.
When should thyroid hair loss be investigated further?
Further assessment is appropriate when hair loss is:
- Sudden
- Severe
- Patchy
- Associated with scalp inflammatio
- Associated with scarring
- Continuing despite normal thyroid levels
- Associated with significant fatigue or other systemic symptoms
It is also worth reassessing if hair continues to thin for many months after thyroid function has normalized.
Vitamins for thyroid hair loss are most useful when a true deficiency exists, while iron deficiency, menopause, stress, illness & genetics should also be considered when hair loss continues.
The naturopathic approach to thyroid hair loss
A naturopathic assessment should look beyond the scalp.
Depending on the individual, this may include:
- TSH and free T4
- Thyroid medication and absorption
- Ferritin and iron status
- Vitamin B12
- Vitamin D
- Zinc when appropriate
- Protein intake
- Menstrual history
- Menopause
- PCOS
- Recent illness
- Stress
- Weight changes
- Medications
- Scalp health
The goal is to determine which factors are actually contributing. For a more complete wellness assessment, naturopathic care for hair loss may help explore thyroid function, nutrition, stress, lifestyle, and other possible contributors alongside regular medical care. For one person, correcting hypothyroidism may be enough. Another may also have low iron stores. Someone else may have female pattern hair loss that happens to occur alongside thyroid disease. In my opinion, identifying that distinction is much more useful than simply taking a generic "hair and thyroid" supplement.
Final Thoughts
So, does hypothyroidism cause hair loss? Yes.
Low thyroid hormone levels can disrupt the normal hair-growth cycle and contribute to diffuse shedding, dry hair, brittleness & slower growth. However, thyroid hair loss is only one possible explanation for thinning hair. Iron deficiency, menopause, stress, rapid weight loss, medications, autoimmune disease & genetic hair loss can produce similar symptoms.
Through nearly two decades of clinical practice, I have observed that hair concerns often require patience. Thyroid blood work can improve before the hair does because follicles need time to cycle back into active growth. In my opinion, the most useful approach is to treat the thyroid appropriately while also looking for other correctable contributors. Hair loss should not automatically lead to a long list of supplements. It should lead to a thoughtful investigation of why the hair is shedding and what the body may need to restore normal growth.
Hair Loss With Hypothyroidism May Need More Than Surface Level Care
If hypothyroidism has left you concerned about hair thinning, low energy, stress, digestion, or changes in overall wellness, Aspire Natural Health may help you explore the bigger picture. Our naturopathic team can review nutrition, lifestyle, thyroid related factors and wellness patterns alongside your regular medical care. Book a consultation to better understand what may be affecting your hair and health.
FAQ’s
Will hair loss from hypothyroidism grow back?
Often, yes. When hypothyroidism hair loss is caused primarily by low thyroid hormone levels, correcting the thyroid problem usually allows the hair cycle to gradually recover. However, regrowth takes time. Hair shedding may take several months to improve & visible restoration of density can take even longer. If hair does not improve after thyroid levels have normalized, other causes such as iron deficiency, genetic hair loss, menopause, or autoimmune disease should be considered.
What are the worst symptoms of hypothyroidism?
The severity of symptoms varies.
Common symptoms can include:
- Severe fatigue
- Cold intolerance
- Constipation
- Weight gain
- Depression or low mood
- Brain fog
- Muscle weakness
- Dry skin
- Hair loss
- Menstrual changes
Severe, untreated hypothyroidism can rarely progress to myxedema coma, which is a medical emergency. Most people do not develop this complication, particularly when hypothyroidism is recognized and appropriately treated.
How to prevent hair loss from hypothyroidism?
The most important step is keeping thyroid hormone levels appropriately treated.
Additional strategies include:
- Taking thyroid medication consistently
- Correcting iron deficiency when present
- Eating enough protein
- Avoiding crash diets
- Correcting identified nutrient deficiencies
- Managing significant stress
- Using gentle hair-care practices
- Investigating persistent shedding
There is no supplement that can reliably prevent hair loss if thyroid hormone levels remain abnormal.
Do people with hypothyroid look younger?
There is no good evidence that people with hypothyroidism consistently look younger.
Hypothyroidism can actually cause changes such as:
- Puffy facial features
- Dry skin
- Coarser skin
- Hair thinning
- Loss of the outer eyebrow
- Swelling around the eyes
These changes can alter appearance, but they should not be interpreted as anti-aging effects. Treating hypothyroidism is important for health, not cosmetic aging.
How do I get my hair to grow with hypothyroidism?
Start by making sure thyroid function is properly controlled.
Then consider other factors that may affect hair growth, including:
- Iron status
- Protein intake
- Vitamin and mineral deficiencies
- Menopause
- PCOS
- Stress
- Recent illness
- Rapid weight loss
- Medications
- Genetic hair loss
Hair regrowth is slow, so give treatment time to work. If shedding remains significant after thyroid levels have normalized, further evaluation may be necessary.
