Why Selenium is a Vital Mineral For Our Hair and Health, According to Science

Selenium is an essential trace element that our bodies need to conduct numerous processes, including normal and healthy hair growth. We get most of our selenium from dietary sources. When this mineral is deficient, various health disorders can develop including hair loss. Likewise, excessive amounts can lead to other types of ailments. These phenomena obviously highlight how important it is to maintain optimal and balanced selenium levels for our hair and general health. But rather than simply accepting this information at face-value, here is a deeper science-based look at why this is the case.

Dietary Selenium, From Nature’s Soil to Its Usage In Our Bodies

Brown rice is an excellent source of dietary selenium
Brown rice is an excellent source of dietary selenium for our hair and general health

Selenium comes from the soil which grows our food, as well as water. The mineral is then taken up by plants and converted to a new, organic form called L-selenomethionine, an amino acid that can be ingested and utilized by humans and animals. It oxidizes quite readily in our bodies. This property allows it to easily reduce and neutralize free radicals which damage our cells.

Good food sources of selenium include:

  • whole grains
  • Brazil nuts
  • brown rice
  • sunflower seeds
  • spinach
  • lentils
  • oatmeal

Yet, the soil concentration availability of selenium varies all across the world. This, of course, affects how much of this mineral we can get from dietary sources. For example, according to Harvard Health, the richest selenium soils in the United States are found in Nebraska, South Dakota and North Dakota. On the other hand, soils in China and Russia tend to be low in selenium. During the 1970’s deficiencies of this mineral resulted in widespread cases of Keshan’s Disease. The name derives from Keshan County of Heilongjiang province, Northeast China where it was first described. The Chinese government then provided dietary supplements of selenium which lowered these incidences.

Selenium deficiencies can also arise when our blood is not able to absorb enough of this mineral. Possible reasons why this occurs include:

  • The use of birth control pills
  • Smoking
  • Alcohol

Low selenium may result in hair loss, fatigue and concentration difficulties.

Within our bodies, selenium is then used to make a class of compounds called selenoproteins responsible for functions like synthesizing DNA, producing thyroid hormones, protecting our tissues from oxidative damage and more. Many of the proteins are enzymes which use selenium as an activating cofactor to catalyze biochemical reactions. Put another way, a severe reduction or lack of this mineral would slow or halt many of the processes we rely upon to maintain our health.

Selenium plays an immensely important role in the production of our thyroid hormones which regulates our hair growth cycles. In fact, no other organ in our bodies contains as much selenium as the thyroid gland. Selenium also supports the white blood cells of the immune system to fight infections. And it is needed to activate many physiological enzymes which act as antioxidants. Some studies are even finding that selenium may also exert anticarcinogenic benefits.

Selenium As A Necessary Mineral For Healthy Hair

Thyroid hormones which require selenium, are necessary for normal hair growth.
Thyroid hormones which require selenium, are necessary for normal hair growth.

When a doctor investigates the cause(s) of a hair loss condition, he or she will check to see if there are any underlying medical conditions at work. A rather common one includes thyroid imbalances (i.e. hypothyroidism and hyperthyroidism) which are commonly associated with telogen effluvium hair loss. Once placed on a thyroid medication prescribed by their doctor, many patients are soon able to see an improvement in their hair growth.

So how exactly do our thyroid hormones regulate normal hair growth cycles? Do they work through a direct, or indirect relationship? Here are a couple of research studies which help provide answers to these questions.

In one study, scientists observed mice which were genetically altered to have missing thyroid hormone receptors in their skin [1]. They were able to conclude that thyroid hormones emit signals which regulate the activities of stem cells found in the hair follicle bulge. These stem cells are responsible for our keeping our hair cycles going. The signaling of thyroid hormones mobilizes stem cells out from the follicle bulge which then facilitates hair growth processes. The authors of this study also note that this explains why mice without skin thyroid hormone receptors show defects in hair growth, as well as epidermal production and wound healing.

In a different study, researchers studied human hair follicles isolated from women undergoing facelift surgeries [2]. They discovered thatthyroid hormones directly target the follicles, working to prolong the anagen phase, stimulate cell division of hair matrix kerotinocytes. These hormones also promote hair pigmentation and downregulate apoptosis.

Selenium is also needed to activate and regenerate antioxidant functioning in our bodies, neutralizing free radicals which contribute to cell and tissue damage, including our hair follicles [3].

Selenium activates antioxidant enzymes in the body which neutralize free radicals that age our hair follicles and other structures.
Selenium activates antioxidant enzymes in the body which neutralize free radicals that age our hair follicles and other structures.

In one review concerning the nutritional needs of menopausal women suffering from hair loss, the authors cited selenium as one of a group of minerals which significantly influence hair growth [4]. Others include zinc, iron, copper, silicon, magnesium and calcium. The review explains that the hair follicles uptake selenium, along with other trace elements from the blood. They then incorporate the mineral into the hair matrix structure during the process of keratinization.

In a study where researchers observed infants suffering from selenium deficiencies, noting that hair loss was one of the key symptoms that resulted as a consequence in all six subjects [5]. Others included growth retardation and pseudoalbinism.

Besides its internal roles in the biological processes of our bodies, topical selenium also plays an important role by killing the fungal organism which causes dandruff. For this reason, selenium sulfide is often used as the main active ingredient in many dandruff treatments. Microbe proliferation in our scalp is not only undesirable due to skin flaking, but also the inflammation which occurs due as the immune system tries to eliminate these organisms, but attacks and damages our hair follicles in this process.

Other Benefits of Selenium For Our Health

Balanced selenium levels, along with other nutrients keep our hair and bodies in shape
Balanced selenium levels, along with other nutrients keep our hair and bodies in top-notch shape

Recent studies are investigating the possibility that selenium may offer protective benefits for our skin against UV-induced damage. Findings are not yet conclusive at this point. But the concept of an internal form of sunscreen has been a source of fascination for scientists. Nonetheless, the antioxidant promoting activities of selenium still contribute to anti aging effects for the skin and other tissues.

Selenium has also gained enormous attention due to evidence pointing to the lowered risk of certain types of cancers. One review of 69 studies showed that 350,000 individuals with high blood concentrations of selenium had much lower incidences of certain cancer types such as prostate, lung, breast and colon cancer.

Also, the effects of oxidative stress is not just limited to the general signs of aging. Free radical damage can be severe enough to affect our mental functioning. Oxidative stress is associated with neurological conditions like Alzeimers, multiple sclerosis and Parkinson’s disease. A few studies discovered that Alzeimers patients had lower-than-average selenium levels in their blood.

In one published study, patients with mild forms of cognitive impairment were given one Brazil nut a day, a food source rich in selenium. To the surprise of the researchers, these individuals showed various signs of improvement across different mental functions, including verbal fluency.

The benefits offered by selenium for our hair and bodies are certainly remarkable. However, we should always keep in mind that our health depends on a wide, comprehensive range of different nutrient types, working together not just one. The right balance, which can be made available through some oral or topical hair products, is essential for produce the most optimal results.



[1] Constanza Contreras-Jurado et. al, Thyroid hormone signaling controls hair follicle stem cell function, Molecular Biology of the Cell Vol. 26, No. 7

[2] Nina van Beek et. al, Thyroid Hormones Directly Alter Human Hair Follicle Functions: Anagen Prolongation and Stimulation of Both Hair Matrix Keratinocyte Proliferation and Hair Pigmentation, Journal of Clinical Endocrinology & Metabolism 93(11):4381-8 · September 2008

[3] Ujang Tingg, Selenium: its role as antioxidant in human health, Environ Health Prev Med. 2008 Mar; 13(2): 102–108.

[4] Zuzanna Sabina Goluch-Koniuszy, Nutrition of women with hair loss problem during the period of menopause, Prz Menopauzalny. 2016 Mar; 15(1): 56–61.

[5] Kouji Masumoto MD et. al, Clinical features of selenium deficiency in infants receiving long-term nutritional support, Volume 23, Issues 11–12, November–December 2007, Pages 782-787


Frequently Asked Questions – Selenium Benefits For the Hair

How much selenium should I be taking for better hair growth and my general health?

The standard recommended daily intake of selenium is 60 micrograms for men and 53 micrograms for women. Higher dosages are permissible under the guidance of a physician. For example, in a study on prostate cancer, subjects took 200mcg of selenium a day. However, the safe upper limit has been defined as 400 micrograms a day for adults. Excessive selenium can result in a condition called selenosis, marked by hair and nail loss, bad breath, fatigue and damage to the nerves.

Is selenium better than biotin for the hair?

Although biotin has developed a strong reputation as a hair supplement vitamin, its benefits are apparent when it is deficient to start with. Selenium, biotin and other nutrients are needed in the right balanced dosages to produce long-term benefits for the hair and other areas of our health.


Further Reading

Learn more about the role of biotin in supporting healthier hair

Discover how green tea may help our hair follicles reach a more optimal state



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