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Thyroid Hair Loss: How Do Your Thyroid Levels Affect Your Hair?

Thyroid hair loss is a common issue among people with thyroid disorders or people with autoimmune diseases that are linked to thyroids.

Weight gain or weight loss are not the only side effects of thyroid disease. These types of thyroid dysfunctions can cause hormonal imbalances, and they can indirectly cause hair loss.

We will be covering this information on thyroid and hair loss:

  • OVERACTIVE, UNDERACTIVE, OR INACTIVE THYROID CAN CAUSE HAIR LOSS.
  • THYROID-RELATED HAIR LOSS CAN BE IDENTIFIED VIA ITS SYMPTOMS.
  • HAIR CAN GROW BACK WHILE STILL HAVING A THYROID DISEASE OR AFTER IT’S BEEN TREATED.
  • NUTRITION IS A KEY FACTOR TO HELP WITH THYROID HAIR LOSS.
  • THYROID MEDICATION OVERDOSE CAN ALSO CAUSE HAIR LOSS.

Can Thyroid Cause Hair Loss?

Yes, thyroid can cause hair loss under certain circumstances. Thyroid hormones play a massive role in the hair growth cycle. It can be said that there is a connection between hair loss and thyroid.

If the thyroid hormone levels are affected or interrupted, it affects the whole cycle. If it is overactive, underactive, or inactive, it can lead to hair loss.

Can Overactive Thyroid Cause Hair Loss?

Yes, having overactive thyroid glands (hyperthyroidism) can cause hair loss. Hyperthyroidism leads to having excess thyroid hormones. This throws off the hair cycle, affecting it negatively and causing hair loss.

When thyroid hormones stimulate cells for a long time, it can slow down hair growth. It can also promote the development of certain types of cells called K15-positive progenitor cells (cells that can develop into other cells). This decreases the stem cells, causing hyperthyroidism hair loss.

Can An Underactive Thyroid Cause Hair Loss?

Yes, inactive or underactive thyroid glands (hypothyroidism) can cause hair loss.

When the production of thyroid hormones is insufficient or nonexistent, this affects lots of functions in the body including hair growth.

Hair falls out normally, 50-100 strands a day, but isn’t replaced by new and growing hair. This later leads to hypothyroid hair loss.

Does Thyroid Cancer Cause Hair Loss?

Thyroid cancer itself does not usually cause hair loss. Not even as a symptom. However, certain treatments for thyroid cancer can cause hair loss as a side effect. The thyroid cancer treatments that can cause hair loss are:

  • THYROIDECTOMY SURGERY
  • RADIATION THERAPY
  • CHEMOTHERAPY


During a thyroidectomy, thyroids are removed. This means that patients can observe hair loss after thyroidectomy.

How To Understand Your Hair Loss Is Due To Thyroid

If you are already diagnosed with a thyroid disease, your hair thinning and eyebrow thinning can be explained by that condition. However, you may have not yet been diagnosed with a thyroid disease.

You can see some signs of thyroid hair loss if you indeed have a thyroid disease.

  • BALD SPOTS
  • BRITTLE HAIR
  • DANDRUFF
  • DRY AND ITCHY SCALP
  • DRY HAIR
  • FASTENED OR SLOWED HAIR GROWTH
  • HAIR THINNING
  • LESS HAIR ON OTHER PARTS OF YOUR BODY
  • THINNING EYEBROW
  • TOO SOFT AND FINE HAIR

What Does Thyroid Hair Loss Look Like?

Thyroid-related hair loss looks like diffuse hair loss and occurs on the entire scalp. It does not occur in patches. Bald spots can be seen, but they do not have an exact patchy look. It can weaken the hair greatly. They look brittle, thin, and dry. In other words, the hair might look very unhealthy.

How to Stop Thyroid Hair Loss

First, one needs to address the issue behind it. Once that is addressed, then it is time to apply the appropriate method. 

To help stop the hair loss and promote hair growth, you need to:

  • GET ENOUGH PROTEIN AND IRON
  • EAT ANTI-INFLAMMATORY FOODS
  • TAKE MULTIVITAMINS


It is important to watch your nutrient values when you are dealing with thyroid-related hair loss. Also, these may or may not work for everyone. They can help slow the process, but might not be able to stop it altogether. 

However, in the case of severe hair loss and no hair regrowth, there is one sure way of stopping thyroid hair loss: Hair transplant surgery.

Hair Transplant for Thyroid Hair Loss

A hair transplant surgery consists of moving donor hair follicles to the needed, balding parts on the scalp. It is a highly demanded treatment option for people with thyroid hair loss, especially people with hyperthyroidism.

In the case where hair growth does not occur within 69 months after the hair loss stops, it can be considered a way to go.

Hair Loss Due to Thyroid Will It Grow Back?

Absolutely yesAutoimmune thyroid diseases, do not affect the hair follicles in a way to make them stop functioning.

So, regrowth is not only possible after thyroid disease hair loss, but it is also almost 100% guaranteed.

However, to apply the appropriate hair growth method, it is important to address the right issue behind it. Your thyroid might be connected to your hair loss in these ways:

  • YOU HAVE HYPERTHYROIDISM OR HYPOTHYROIDISM
  • YOU ARE USING THYROID MEDICATION(S)
  • YOU HAD THYROIDECTOMY TO TREAT HYPERTHYROIDISM
  • YOU HAVE OTHER AUTOIMMUNE DISEASES LINKED TO THYROID ISSUES

Can an Endocrinologist Help with Thyroid Hair Loss?

Yes, an endocrinologist can help treat hair loss, provided the reason behind the hair loss is hormonal.

Endocrinology is the study of hormones. Hormonal imbalance is a known cause of hair loss. An endocrinologist can provide treatment concerning those issues.

Can Thyroid Medication Cause Hair Loss?

Yes, some thyroid medications can cause hair loss as a side effect. It is usually temporary. Meaning the hair can grow back in time.

Does Synthroid Cause Hair Loss?

Yes, Synthroid hair loss can happen as a side effect. However, the chances of hair loss occurring under this treatment are rare.

Some people can observe partial hair loss or thinning a few months after starting the treatment.

Can Levothyroxine Cause Hair Loss?

Yes, levothyroxine can cause hair loss. But, it is less common than it is feared to be. Levothyroxine is prescribed for the treatment of hypothyroidism. Due to inactive thyroid glands, there can be an occurring hypothyroidism hair loss at hand, and starting this treatment can accelerate it. 

Why does levothyroxine cause hair loss, though? There might be some reasons for that. These can be:

  • HORMONAL IMBALANCE
  • NUTRITIONAL DEFICIENCIES
  • OTHER UNDERLYING MEDICAL CONDITIONS
  • GENETICS
  • INCORRECT DOSAGE
  • INDIVIDUAL BODY RESPONSE TO THE MEDICINE


However, the shedding will stop and hair regrowth can be observed in a short amount of time provided the medicine is used appropriately.

Does Too Much Thyroid Medication Cause Hair Loss?

Yes, too much thyroid medication can cause hair loss. There are main treatments for hypothyroidism and hyperthyroidism. For hypothyroidism, it is levothyroxine. Medications like these can cause 2 types of hair loss: telogen effluvium and anagen effluvium.

Hypothyroidism medications can cause telogen effluvium while hyperthyroidism medications can cause anagen effluvium.

For hyperthyroidism, it is carbimazole and propylthiouracil. These drugs can cause minor hair loss as a side effect. However, using too much of them, or in other words overdosing on them, can cause hair loss.

(1) Contreras-Jurado, C., Lorz, C., García-Serrano, L., Paramio, J. M., & Aranda, A. (2015). Thyroid hormone signaling controls hair follicle stem cell function. Molecular biology of the cell, 26(7), 1263–1272.

(2) Kumar, K. J., Kumar, M. S., Kumar, T. S., & Chavan, A. (2015). Diffuse scalp hair loss due to levothyroxine overdose. Indian Dermatology Online Journal, 6(Suppl 1), S58–S60. 

(3) Messenger A. G. (2000). Thyroid hormone and hair growth. The British journal of dermatology, 142(4), 633–634.