Informational Posts / My Personal Experiences

Hair Loss and Thyroid Disease (Hypothyroidism and Hashimoto’s)

Originally published on 6th December 2016
Last updated on 25th March 2024

Losing your hair can be very upsetting. It’s not just vanity, hair also contributes to your identity and is yet another way that hypothyroidism can wreak its havoc. It can make things feel out of control, as you stare at another clogged shower drain of hair.

In this article, we are going to cover the many possible causes and treatments for hair loss in relation to thyroid health. 

This photo was taken in 2024, but I haven’t always had healthy, thick, fast-growing hair like this.

The Truth about Miracle Hair Products 

Before you spend a lot of time and money on shampoos and ‘miracle’ hair loss products trying to treat the symptom (hair loss), you should, I recommend, explore all the possible causes for the hair loss in the first place. No shampoo is going to encourage hair growth or stop it thinning, it will just make it appear thicker. It won’t be a miracle product!

Treating the actual cause is the best approach to saving your hair.

I Lost Most My Hair 

I’ve experienced drastic hair loss myself, where I lost about 80% of my hair after a hospital stay in intensive care with pneumonia, prior to my diagnosis of hypothyroidism and Hashimoto’s (although the Hashimoto’s was ramping up at the time).

Hair Loss With Underactive Thyroid

I had a type of hair loss called telogen effluvium, which basically occurred because the severe illness I was going through at the time caused a drastic shock to the growing follicles. So much so that they went into a resting state, resulting in an increase in hair shedding and thinning of hair on the scalp. This type of hair loss often develops suddenly, although typically a month or two after the initial shock. In my case, it was a month after I left hospital.

As the trigger was short lived, the hair follicles returned to their usual growing state after about three months of shedding (by which point I had incredibly thin hair) and started producing new hair fibres fairly quickly.

Rachel Hair Loss HypothyroidismHair Loss With Underactive Thyroid

After six months or so of the new hair starting to grow and come through, my hair was looking much healthier and thicker, although the new hair that came through was like baby hair!

Since then, my hair has been the thickest it has ever been, but I wouldn’t wish going through the trauma of hair loss on anyone.

My healthy hair these days

I’ve also experienced thinning of eyebrow hair, which I haven’t found so bad, as makeup allows us to ‘fix’ this easier than head-hair. However, this can also knock your confidence and be another frustrating physical demonstration of how unwell you feel. Read my article on how I got my eyebrows to fully grow back here.

However, hair loss can occur for a myriad of other reasons, especially when you also have a hormonal imbalance such as hypothyroidism, so I’m going to explore these below.

If you are experiencing hair loss, please ensure you explore as many of these as possible.

Related Article: Can Hypothyroidism Cause You To Not Retain Hair Dye?

Possible Causes of Hair Loss in Thyroid Patients 

1. Non-Optimised Thyroid Hormone Levels

Optimised thyroid levels are different to just being ‘normal’ or ‘in range’. Optimal levels are a more specific section within the given range, which is often very wide and much less specific in comparison.

When testing a thyroid panel (or “Thyroid Function Test”), a TSH less than 2 or 2.5, and a Free T3 in the top quarter of the range, with a Free T4 mid-range or a little higher is generally considered optimal. More info here.

Thyroid antibodies (a measurement for Hashimoto’s) as low as possible are also seen as optimal, as this signals Hashimoto’s being more under control or ‘in remission‘. High thyroid antibodies are often linked to hair loss.

Note: You can order your own full thyroid panel online, which can be a great option if your doctor won’t run all the tests. Find a UK option here and a US link here.

Under medication of hypothyroidism, which often shows as TSH being high and Free T3 and/or Free T4 being low can be a cause for hair loss. Many thyroid patients find that they require a thyroid medication with direct T3 in to reach optimal thyroid levels.

However, overmedication with thyroid hormone replacement can also cause hair loss, as can your thyroid levels swinging from hypo to hyper (those with Hashimoto’s and/or Graves’ may experience this). Too much thyroid hormone is also not a good thing.

Related post: It Is Possible To Have Graves’ AND Hashimoto’s

Hair loss may also happen due to shifting thyroid hormones while you adjust to a new dosage of thyroid medication. When your dose and levels have stabilised, the hair loss may also stop.

2. Low or Deficient Nutrient Levels

Probably the most common nutrient with its links to hair loss, is iron.

Ferritin is the stored form of iron and is usually the first thing doctors check when you experience hair loss. This is especially important when you suffer from Hashimoto’s or hypothyroidism, because having low ferritin levels is fairly common with these.

I was given iron tablets for my low ferritin levels at the same time as a diagnosis of hypothyroidism and Hashimoto’s. However, you also want to ensure that your ferritin levels are optimal, before ticking this off your list as not the culprit for your hair loss.

Test results for Iron, Ferritin, T.I.B.C., Transferrin Saturation etc. should all be well within range to help avoid symptoms. Although a ‘normal range’ for women on many tests for iron is 20-200ng/mL, a lot of thyroid patients find that their symptoms improve upwards of 70ng/mL. The optimal ferritin level for thyroid function is between 90-110 ng/mL.

I wouldn’t recommend supplementing iron unless you know for sure that you’re low in it, as taking it when you don’t need it can be harmful.

With supplementing, iron bisglycinate is often preferred over other types of iron as it is gentler on the stomach and is less likely to cause constipation.

As Well as Ferritin, It’s Also Worth Considering Other Vitamin Levels Such as Vitamin D, Zinc, Magnesium, B12 and Folate

The Vitamin D receptor is expressed in numerous cells and tissues of the body, including the skin. Studies of mice and humans lacking these functional receptors have demonstrated that absence of the VDR leads to the development of alopecia, another word for hair loss. (More on alopecia below).

Vitamin D supplementation is hugely popular, as many of us are low in this hormone, but you should always look in to taking K2 along with D3. K2 regulates calcium in the blood, so combining Vitamin K2 with Vitamin D3 is highly recommended because of the synergy between the two vitamins. Research shows a slower progression of calcification in those taking both vitamin K2 and vitamin D compared to those taking vitamin D alone.

Zinc plays a role in cell reproduction as well as hormonal balance, and these functions can affect your hair growth. Zinc even manages the glands that attach to your hair follicles, which is very interesting. When your zinc levels are low, these follicles can become weak, causing strands to break off or fall out. Read more about how so many of us with thyroid conditions are deficient in zinc, here.

Iodine – low or high – can also cause hair loss. Do not guess with this one, supplementing iodine when you do not need it can be dangerous.

Magnesium facilitates the release of energy from foods. It helps the body absorb nutrients, including those needed for hair health and hair growth.  Therefore, low levels of magnesium in the body could be affecting your hair, too. Magnesium Malate and Chelate is the most popular among thyroid patients.

B12 and folate (B6) can also affect your hair. Healthy hair growth is dependent on synthesis of DNA and adequate B12 levels, so a potential sign of Vitamin B12 deficiency can be hair loss.

The very popular Biotin (B7) is also a popular hair supplement, however, biotin supplements are only likely to prevent hair loss and promote hair growth in people with an actual biotin deficiency. It is also worth knowing that biotin supplements can cause thyroid test results to come back inaccurate, so always stop them at least 48-hours before your test. More info on this here.

The amino acid L-tyrosine is responsible for skin and hair pigment as well as strong, healthy hair. Supplementing may therefore help. However, it’s worth knowing that it can increase Free T3 and Free T4 levels, and affect your thyroid medication dosage.

Others find success with collagen supplements.

As with all supplements, it’s not wise to take them unless you know you need them via testing first. You should always let your doctor know about starting new supplements too.

3. Alopecia

You’ve probably heard the name of this form of hair loss before.

Alopecia Areata tends to cause bald spots on the scalp as oppose to overall thinning and is an autoimmune disease, as the immune system attacks the hair follicles. This is particularly interesting, as those of us with Hashimoto’s Thyroiditis, the autoimmune cause of hypothyroidism (about 90% of us with hypothyroidism have this [1]), are by default at a high risk of developing other autoimmune diseases, such as Alopecia Areata.

Please also note that tight hairstyles especially if worn daily (e.g. high ponytails, buns, braids) may make any underlying hair loss worse.

4. Adrenal Dysfunction

Adrenal dysfunction (note: it is more accurately referred to as hypothalamic-pituitary axis dysfunction) may also be behind hair loss, due to the link with stress levels and the stress hormone cortisol.

If your doctor won’t check your adrenal health (cortisol levels), you can very simply order testing yourself here and here.

5. Diet

Blood Sugar Imbalances

Unstable blood sugar is something I’ve covered before, here, and it’s something that places extra stress on our adrenal health.

When your blood sugar levels drop below normal, your adrenal glands respond by secreting cortisol. This cortisol then tells the liver to produce more glucose, which brings blood sugar levels back to normal. Doing this repeatedly can cause abnormal cortisol output, and, as I’ve already covered above, abnormal cortisol (such as adrenal fatigue) levels can be detrimental to your hair.


I’ve also heard from thyroid patients who found sensitivities to food such as gluten, dairy, eggs etc. caused them hair loss, and eliminating them from their diet helped hair to regrow and also become stronger and healthier.

Foods you can eat to promote good hair health include those high in Omega-3 Fatty Acids, including salmon or other oily fish. You can also supplement if easier.


Many thyroid patients reduce calories in a bid to manage the thyroid symptom of weight gain, only to find that the stress of this (and not getting enough of the right types of foods) can also cause hair loss. Dieting may also reduce thyroid hormone levels further.

6. Low Stomach Acid

Low levels of stomach acid, commonly experienced among thyroid patients and especially those on T4-only medications, can contribute to hair loss. This is due to stomach acid aiding your ability to digest crucial nutrients and protein used in hair growth.

You can take two tablespoons of apple cider vinegar in a glass of warm water (with a straw to protect teeth) and a digestive enzyme with each meal to aid digestion and stomach acid, helping to absorb more of those important nutrients from food. But again, we all react differently and not everyone will benefit from these practises. Symptoms of low and high stomach acid are very similar!

Some people also find that adding a daily probiotic helps, as it can help to balance out the good and bad bacteria in the gut and exploring your gut health and addressing any underlying candida (an online UK test for Candida can be found here and a US test here), infections etc. may help to improve not only hair growth but your overall health; including energy levels and skin complaints. Read more about your gut health here.

7. Other Medications

There are some medications that can cause hair loss, including hormonal contraceptives, retinoids (used for severe acne), antibiotics, antidepressants, anti-convulsants (used for epilepsy), beta-blockers, NSAIDs, steroids, cholesterol lowering medicines, cancer treatments,  and many more.

Make sure you check the listed side effects of any medications you are using and consult your doctor if you believe any could be causing you hair loss. Never stop any medication suddenly – always use the guidance of a medical professional.

8. PCOS 

On average, women with PCOS (Polycystic Ovary Syndrome) tend to have higher TSH levels and be subclinically hypothyroid when compared to controls of the same age without PCOS. Hypothyroidism, and in particular, Hashimoto’s, is more common in women with PCOS than in the general population. High levels of thyroid antibodies are found in one in three PCOS patients [2].

Do any of the following signs and symptoms sound like you?

Read more here.

9. Menopause

The menopause and peri-menopause can also lead to hair loss, and due to thyroid conditions often being diagnosed around middle-age, having these at the same time is not uncommon.

The link is thought to be due to declining oestrogen levels, but checking testosterone levels can also be helpful. Too high or low and hair loss may occur.


Even when we figure out the cause for our hair loss, hair can take several months to respond to or recover from problems and you can get initial hair loss when your hair cycle restarts after a problem.

It is worth knowing that UK laboratory service Medichecks offer a Hair Loss blood test which checks many of the common causes for hair loss listed in this article.

Be Your Own Thyroid Advocate Book Girl HoldingSee also:

The book Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tiredwhich gives you more need-to-know thyroid patient information like this article!

Have you experienced hair loss with your thyroid condition? What has helped? Feel free to share in the comments below. 




About Author

Rachel Hill is the highly ranked and multi-award winning thyroid patient advocate, writer, speaker and author behind The Invisible Hypothyroidism. Her thyroid advocacy work includes writing articles, authoring books, producing her Thyroid Family email newsletters and speaking on podcasts and at events about the many aspects thyroid disease affects and how to overcome these. She is well-recognised as a crucial and influential contributor to the thyroid community and has a large social media presence. Her bestselling books include "Be Your Own Thyroid Advocate" and "You, Me and Hypothyroidism".


  • Susan Brown
    July 6, 2022 at 8:48 pm

    My daughters hair loss started right after starting levothyroxine. She had beautiful thick shiny auburn hair. Now I can see the scalp peaking out around the crown. Its dull and lifeless. It happened right after starting levothyroxine. My endo said synthroid brand might not make hair fall out. Tried it but still falling out. What can be done if meds cause the hair loss. I csnt imagine anyone going through all those ways to find the cause of hair loss. If it starts right after starting levo wouldnt that point to levo as being the cause?

    • Laura
      July 23, 2023 at 3:12 am

      Susan, did your daughters hair loss ever improve? I am going through the same thing with my daughter.

  • Ellen Roux
    December 20, 2021 at 8:14 am

    I’ve been diagnosed whit Hypothyroidism on the 2 off November my thyroid is dead doctor sed for some unexplained reasons my thyroid died I’m on thyroid med for the rest of my life went for blood work again on the 17 off December waiting for results but I’m left in the dark my Doctor did tell me anything off what’s going on or what’s going to happen to me my ths was 94 and Doctor sed it’s life threatening hi and it need’s to go down to 4
    I’m feeling really bad for a long time
    Hair loss
    Sore mussels especially my back muscles stiff sore
    Sore sometimes painful rib cage
    Sore neck and shoulder
    Cold ore hot
    Weight loss
    Extremely extremely tired
    I would like to know what’s the next step and because my thyroid is dead do they have to remove it
    I’m scared because I’m left in the dark not knowing what’s going on

  • Linda
    September 13, 2021 at 2:09 pm

    I am find a lot of info regarding low iron levels. Where can I find info regarding high ferritin levels?

    • Linda
      October 20, 2021 at 12:07 am

      Great question! I would also be interested in high ferritin level info.

  • Nichole
    March 26, 2021 at 11:03 pm

    Armour thyroid has been well-known to cause hair loss within the first few months of treatment. For those of us using it, I feel it is important to normalize that issue in this exact instance, however it is also a necessity to talk to your doctor in case of other underlying issues.

  • Marcia
    July 27, 2020 at 8:53 pm

    Has anyone ever found a way to improve thin & brittle hair resulting from postmenopausal Hashimoto’s? There are hyped ‘remedies’ out there, but none seem to actually work (you can tell by the ads — if success is based on comments rather than measurements, it’s not true).
    If you’re over 55 and have found something that works, please post it.

  • Anita
    July 27, 2020 at 12:14 pm

    I’ve been on levothyroxine for 4 years now. I don’t have hair loss in my head – noticed most recently on my eye brows – the ends. What can help grow them back ? If anything.

    • Selma
      February 12, 2021 at 1:23 am

      In last 4 years I have lost 50 % of my hair. 2 years ago when I noticed the most lost I cut of most of my hair and did cryotherapy. It was scary after the therapy, because most of dead hair fall of in bunches. I almost had no hair in front. I started using zinc and magnesium suplaments and supplements for hair by Herz, together with Anaphase shampoo. My hair grow back, but the quality of hair is still bad. Hair strings are so thin. Unfortunately I live in a country where no one cares about hair loss, especially on a patiant with several nasty diagnosis. I must say besides being diabetic and having hypothyroidism this problem is also psychological. It is hard for a woman to loose hair. I am currently on Euthyrox pills for my thiroid. I thank you very much for this article. I will try to follow it trough and find solution for my hair loss.

  • Peggy Burnett
    January 13, 2020 at 12:52 pm

    I do agree with the fact that there is a link existed between hair loss and hypothyroidism. Hormonal imbalance is very common and is primarily triggered by aging.

  • sterusa
    February 3, 2018 at 12:48 pm

    Hi! Thank you…Excellent article.


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