Hair Loss and Thyroid

A hair loss of 50 to 100 strands per day is common, but if you notice thinning of hair or bald patches on your head, then it’s a more complicated situation.

This form of hair loss, known as alopecia, occurs due to a variety of factors. However, it is also very common in thyroid disorders. Not only is the thyroid hormone essential for many bodily functions, it is vital for the development and maintenance of hair follicles as well.

Although hair loss is one of the distressing thyroid dysfunction symptoms due to its effect on physical appearance, it is something that can be resolved with proper treatment and hormone stabilization.

Hair Loss: An Overview

Alopecia, also known as hair thinning or hair loss, is divided into two types: scarring, wherein the hair follicles are damaged, and non-scarring, where destruction of the hair follicles can be reversed.

The latter is the case in patients with thyroid disorders.

Symptoms of non-scarring alopecia include loss of hair in circular areas or all over the head, brittle hair, even loss of other hairs such as the eyebrows, eyelashes, and pubic hair.

Hair loss can occur due to a variety of causes. Thyroid disease has been a known cause of hair loss, and this will be discussed in the next chapter.

In fact, autoimmune disorders of the thyroid such as Hashimoto’s disease oftentimes co-exist with alopecia areata, another autoimmune condition which manifests hair loss in a patchy or diffuse pattern.

Other causes include anemia, chemotherapy, radiation therapy, scalp ringworm, anorexia nervosa/bulimia, and trichotillomania.

The hormonal changes associated with menopause and childbirth can also bring about hair loss.

Weight loss of more than 15 pounds, a diet poor in protein or iron, or a diet high in Vitamin A can also lead to the development of alopecia.

Intake of certain medications such as blood thinners, birth control pills, steroids, and medications that treat high blood pressure, heart problems, gout, and depression have also been known to cause hair loss.

Sometimes, the products that you use on your hair or the styles you use can lead to hair loss as well. Frequent use of hair bleach, flat irons, and blow dryers can weaken the strands, and this can consequently lead to hair loss.

Hair Loss and the Thyroid Connection

As it has been said, hair follicles are developed and maintained with the help of thyroid hormones. Abnormalities in the levels of such, as seen in the cases of hypo- and hyperthyroidism, often result in hair problems.

In a study by Van Beek et al, results showed that thyroid hormones T3 and T4 directly affect the follicles of the scalp. T4 has been known to increase the number of hair matrix keratinocytes, which protect the hair from environmental damage and the hair loss that usually comes with it.

Similarly, T4 helps prolong the anagen phase or the growth phase of hair.

Because of the effect of the thyroid hormones on hair, it follows that a lack or surplus of these can lead to hair problems.

Both hypo- and hyperthyroidism have been linked with telogen effluvium, which is the second most common form of hair loss. In this case, there is a drop in the number of hair follicles during the resting phase of hair growth. Increase in hair follicles occur during the dormant phase, and this leads to the hair loss symptom common in thyroid disorders.

Apart from hair loss, a characteristic change in your locks can determine the thyroid disorder that you have. Hypothyroidism comes with dull, dry, and brittle hair shafts, while hyperthyroidism has been associated with greasy, brittle hair with a thinner shaft diameter.

Hair Loss and Thyroid Treatment

While correcting thyroid hormone levels can stop the hair loss caused by related conditions, thyroid treatments can also bring about the same problem. Such is the case with levothyroxine, which is prescribed in patients suffering from hypothyroidism.

One of its side effects is hair loss, especially in children, during the first month of levothyroxine therapy.

Apart from use in routine treatment, overdosage of Levothyroxine can also lead to pronounced hair loss. Such was seen in the case of a 10-month-old child in India, who was diagnosed with hypothyroidism and was treated with Levothyroxine. However, 10 days after the start treatment, he began to lose scalp hair, while the hair that remained on his head appeared to be thin and easily pluckable. The patient’s lab results showed excessive levels of Serum T4 due to an overdose in Levothyroxine treatment.

In this case study of Kumar et al, the physicians reduced the Levothyroxine dose by 50% to address the hair loss problems. Follow up done 15 days after still showed high levels of T4, which followed another reduction in Levothyroxine dose. After proper dosing, the child showed regrowth of hair and no further hair loss was noted.

As with hypothyroidism medications, hyperthyroidism drugs also come with the side effect of hair loss as well. It is often expected following treatment with either Propylthiouracil or Methimazole.

Adherence to Proper Thyroid Treatment: Key to Preventing Hair Loss

Thyroid disorders and overdose can pave the way for dramatic hair loss, as it has been seen in the child mentioned above. As such, it is important that you follow your physician’s treatment regimen properly in order to prevent further balding.

First and foremost, make sure you are taking the right drug, at the right dose, route, and time. As it has been mentioned in the previous chapter, an overdose in Levothyroxine treatment can lead to profound hair loss. Under dosage, on the other hand, will not cure the underlying thyroid problem that causes the symptom hair loss.

In essence, it is important that you adhere with your doctor’s prescription. Avoid increasing or decreasing the dose without the advice of your doctor. Most importantly, don’t switch brands abruptly by virtue of price, fad, or any other factor.

Remember that hair loss is expected with Levothyroxine, as well as Propylthiouracil and Methimazole treatment. Should the manifestation last longer beyond the one-month mark, consult with your physician right away.

Secondly, remember to undergo Thyroid testing to determine your hormone levels regularly. Even if you are adherent to your medication regimen, you need to have your blood checked to see if your treatment dosage is still right for you. By doing so, you can correct the levels of thyroid hormones which might be wreaking havoc on your hair health.

More Tips on How Prevent Hair Loss

While hair loss commonly occurs in thyroid disorders – and in treatment too – you can control the severity of your alopecia by heeding the following health tips:

  • Eat food that can reduce hair loss

Apart from normalizing your thyroid hormones, a diet rich in certain vitamins and minerals can help restore your crowning glory.

For one, eat food rich in iron and B-vitamins, such as sea and dark leafy vegetables, and whole grains. A deficiency in iron is a well-known cause of hair loss, although the mechanism behind this still remains unclear, according to a study by Guo and Katta. The case is similar with Vitamin B3 or Niacin, the lack of which can lead to pellagra. Hair loss is one of the presenting symptoms of this deficiency.

A diet rich in anti-oxidants can also curb hair loss. Fares such as peppers, squashes, tomatoes, cherries, and blueberries can help maintain the integrity of hair, as well as preserve hair luster and color, as stated in a study of Fernandez et al.

Lean meats such as cold-water fish, and healthy oils such as coconut or fish oil, should be incorporated in your daily diet as well.

Hydration is key for optimum hair health, so do remember to drink 6 to 8 glasses of water daily.

  • Avoid food that promote hair loss

While there is no single food that can lead to alopecia, there are some whose ingredients can do more harm than good. Red meats, stimulants, and food with refined sugar, trans-fatty acids and allergens might contain substances that can lead to hair loss.

  • Take supplements that promote hair health

If your diet is lacking the necessary nutrients to keep your locks from falling out, then make sure to take any of these supplements that can maintain and strengthen your hair:

  • Multivitamins containing Vitamin A, E, and minerals such as Calcium, Zinc, Manganese, and Selenium
  • Fish oil containing Omega-3 fatty acids, 1 tablespoon or 1-2 capsules daily
  • Vitamin C, an anti-oxidant, 500 to 1000 milligrams daily
  • L-Lysine to prevent hair loss, 500 to 1000 milligrams daily. Note: Avoid taking this supplement with big doses of calcium
  • Vitamin B complex, to prevent stress-induced hair loss, 1 tablet daily


  • Try Herbal Remedies

Herbal remedies such as Gingko Biloba can improve hair health. In a study by Fischer et al, it was determined that Gingko Biloba, an anti-oxidant, can prevent hair loss by supplying the follicles with the nutrients need for growth. To benefit from this, take 40 to 80 mg of Gingko Biloba extract three times a day. Because it causes bleeding, check with your doctor first before you take this supplement.

Other essential oils known to stimulate hair growth include sage, rosemary, and peppermint. Dilute 3 to 4 drops of any of these oils in 1 tablespoon of olive or vegetable oil and apply to affected areas.

  • Destress

Stress affects your health in a lot of ways. Not only can it weaken your immunity, it can lead to hair loss as well. Stress affects the process of hair growth, which then leads to hair loss that is 10 times more than the usual rate!

Apart from consuming a healthy diet and following your thyroid medication regimen, it is important that you maintain a stress-free life by following these tips:

  • Identify your stressors. By recognizing people, things, or events that stress you out, you can try to eliminate any of them from your daily activities.
  • Not only will exercise help you achieve a fitter body, it can help clear your mind from undue stresses that can cause hair loss. That’s because exercise has been known to foster the release of hormones that can make you ‘feel good.’ Perform your favorite exercise at least 30 minutes a day for favorable results on your mental and hair health.
  • Try relaxation activities. Tai chi, yoga, or simply deep breathing can help lower your blood pressure and heart rate. Doing any of these activities can help free your mind from the stresses that lead to hair loss.
  • Sleep well. Getting 7 to 9 hours of sleep nightly will not only work wonders on your eye bags, it can help freshen up and de-stress you as well! With enough rest, you have the energy and the positive outlook to face the stresses that come up with most facets of life.

Thyroid disorders affect various parts of the body, and your hair is no exception. Although this is the case, you can maintain a head full of healthy hair by following these tips on maintaining your crowning glory – even if you have some thyroid dysfunction in the horizon.


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Fischer, T. W., Trüeb, R. M., Hänggi, G., Innocenti, M., & Elsner, P. (2012). Topical Melatonin for Treatment of Androgenetic Alopecia. International Journal of Trichology4(4), 236–245.

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van Beek, N., Bodó, E., Kromminga, A., Gáspár, E., Meyer, K., Zmijewski, M., Slominski, A., Wenzel, B. and Paus, R. (2008). Thyroid Hormones Directly Alter Human Hair Follicle Functions: Anagen Prolongation and Stimulation of Both Hair Matrix Keratinocyte Proliferation and Hair Pigmentation. The Journal of Clinical Endocrinology & Metabolism, 93(11), pp.4381-4388.