The Science of Selenium in Skin Care

Naturally found in certain foods and natural springs, selenium is a mineral with powerful antioxidant properties. It also plays a key role in a variety of functions in the body and supports skin health and appearance. There are several different forms of selenium in skin care, each with unique benefits for your skin. Learn more about what selenium is, who it’s best for, and where to find it in skin care here.

Selenium is a trace element, meaning the body needs it in very small amounts. It plays a crucial role in a variety of important bodily functions, including thyroid function, DNA synthesis, immune system regulation, and antioxidant defense. Selenium is a key component of several important enzymes, most notably glutathione peroxidase, which helps neutralize harmful free radicals and protect cells from oxidative stress.

In skin care, selenium supports the skin by neutralizing free radicals and reducing inflammation. 

Certain forms of selenium, like selenium sulfide, are also used in medicated shampoos to treat dandruff and scalp conditions such as seborrheic dermatitis, due to their antifungal properties.

Because the body cannot produce selenium on its own, we need to obtain it through diet, supplements, or topical skin care products and selenium-rich thermal spring waters.

Selenium is used in a number of skin and hair care applications and comes along with a variety of unique benefits:

• Antioxidant protection. Selenium is needed for antioxidant enzymes like glutathione peroxidase to properly function (3). These antioxidants neutralize reactive oxygen species (ROS), or unstable molecules that damage skin cells, accelerate aging, and contribute to conditions like hyperpigmentation and inflammation.
• Anti-aging support. By protecting collagen and elastin from oxidative damage, selenium helps to slow visible signs of aging, such as fine lines, sagging, and dullness. It also supports DNA repair and can reduce UV-induced aging (4).
• Anti-inflammatory properties. Selenium’s antioxidant activity also helps to reduce inflammation, making it beneficial for conditions like rosacea and eczema. Selenium also helps to regulate the skin’s immune response, making it less reactive to environmental irritants (5).
• Moisturizing properties. By reducing oxidative damage to skin cells and lipids in the skin barrier, selenium helps to support moisture retention and protection from environmental stressors (6).
• Skin-brightening properties. Though not a direct skin-brightening ingredient like vitamin C or niacinamide, selenium can help to improve skin brightness and radiance by reducing oxidative stress, preventing hyperpigmentation by reducing inflammation, and supporting cellular turnover (6).

There are different forms of selenium that are used in skin care depending on the specific concerns the product is targeting.

• Sodium selenite, a form of selenium commonly found in thermal spring water, as well as some moisturizers and serums, is known for its stability and efficacy in skin care. It delivers antioxidant benefits and helps to support the skin’s barrier.

• Selenomethionine is an organic form of selenium often used in dietary supplements, but it may also be incorporated into advanced skincare formulations due to its high bioavailability and antioxidant activity.

• Selenium sulfide is known for its use in anti-dandruff shampoos due to its antifungal properties. It can also be used to treat scalp conditions like seborrheic dermatitis and tinea versicolor. Selenium sulfide is not typically used in facial skin care products due to its potency and potential for irritation.

One popular skin care use of selenium is in thermal spring water sprays, particularly those from La Roche-Posay, a French brand whose identity is deeply rooted in its natural selenium-rich spring.

The town of La Roche-Posay is home to a thermal spring that has been used since the 1600s for its healing properties. Studies have shown that this water is naturally rich in selenium, giving it strong anti-inflammatory and antioxidant properties (7).

When used in a mist or spray, thermal spring water can help to:

• Calm irritation and redness, including that caused by rosacea.

• Soothe post-procedure or sun-exposed skin.

• Protect against oxidative damage.

• Support the skin’s barrier.

It is important to note, however, that the selenium ions found in thermal spring water will not necessarily be listed on the ingredient list, because they occur naturally as trace minerals rather than added cosmetic ingredients. Since they are not included as isolated compounds or in concentrations that require labeling under cosmetic regulations, they are considered part of the water’s overall mineral composition rather than separate active ingredients.

Keep in mind that most skin care products made with thermal spring water will not have selenium listed in the ingredient list, since this is a naturally-occurring compound that is considered part of the water’s mineral content. Other forms of selenium, like selenium sulfide, will be listed on the package.

When used topically in appropriate concentrations, selenium is considered very safe. The Environmental Working Group (EWG) rates sodium selenite as low hazard (1 out of 10), though this varies depending on the specific formulation and concentration. EWG rates selenium sulfide, an ingredient commonly found in dandruff shampoos as a 5 out of 10 due to its potential to cause skin irritation and dryness.

That said, selenium is toxic at high doses when ingested , so always talk to your doctor before starting a selenium supplement. 

Because it is possible to take too much selenium in the form of dietary supplements, it is better to eat a variety of selenium-rich foods in order to meet your daily requirement. Some foods that are rich in selenium include:

• Brazil nuts

• Seafood

• Meat

• Eggs

• Whole grains and legumes

• Sunflower seeds

• Mushrooms

• Spinach

Selenium found in thermal spring water sprays, moisturizers, and serums can deliver powerful antioxidants and anti-inflammatory properties to your skin with no known side effects. Selenium sulfide, used in dandruff shampoos, can be irritating to the skin so should only be used as directed for your skin type.

1. Baumann L., Weisberg, E. Anti-Inflammatory Agents in Ch. 38 of Baumann's Cosmetic Dermatology Ed 3. (McGraw Hill 2022)
2. Baumann, L. Ch. 64 Cosmeceuticals and Cosmetic Ingredients (McGraw Hill 2015)
3. Bjørklund G, Shanaida M, Lysiuk R, Antonyak H, Klishch I, Shanaida V, Peana M. Selenium: An Antioxidant with a Critical Role in Anti-Aging. Molecules. 2022 Oct 5;27(19):6613. doi: 10.3390/molecules27196613. PMID: 36235150; PMCID: PMC9570904.
4. Hartwig, A., Blessing, H., Schwerdtle, T., & Walter, I. (2003). Modulation of DNA repair processes by arsenic and selenium compounds. Toxicology, 193(1-2), 161-169.
5. Duntas, L. (2009). Selenium and inflammation: underlying anti-inflammatory mechanisms. Hormone and metabolic research, 41(06), 443-447.
6. Wei, K., Guo, C., Zhu, J., Wei, Y., Wu, M., Huang, X., ... & Wei, X. (2022). The whitening, moisturizing, anti-aging activities, and skincare evaluation of selenium-enriched mung bean fermentation broth. Frontiers in Nutrition, 9, 837168.
7. Seite, S. (2013). Thermal waters as cosmeceuticals: La Roche-Posay thermal spring water example. Clinical, cosmetic and investigational dermatology, 23-28.