Key points
- Both pyrithione zinc and selenium sulfide have antifungal properties.
- Pyrithione zinc is usually better tolerated compared to selenium sulfide.
- Selenium sulfide may be more effective in resistant cases of dandruff.
- Pyrithione zinc is available over-the-counter, while selenium sulfide is available over-the-counter at a concentration of 1% and at 2.5% by prescription.
Pyrithione Zinc
Pyrithione zinc aka zinc pyrithione is a complex of zinc and pyrithione. It is a broad-spectrum antimicrobial and can prevent the growth of both fungi and bacteria.
Several studies document that its antifungal properties can help decrease the amount of Malassezia on our scalp or skin. This can improve signs and symptoms of dandruff, seborrheic dermatitis, and tinea versicolor.
It can interfere with the nutrient uptake of Malassezia, preventing its growth. In addition, research suggests that it can help in restoring the skin barrier which is often considered one of the underlying factors behind chronic inflammatory skin conditions.
There is some evidence (2003 study) that it may help in hair growth.
Concentration used
- In shampoos, cleansers, or bar soaps, it can be used at a concentration of 0.3 to 2 percent
- In lotions and creams (leave-on products), it can be used at a concentration of 0.1 to 0.25 percent.
Side effects
Although it is well tolerated, it can lead to side effects in some people like skin irritation, burning sensation, or blistering.
There are very few case reports of allergic contact dermatitis with zinc pyrithione.
Read more: Pyrithione zinc for face
Selenium sulfide
Selenium sulfide is a compound that is often used to treat dandruff, seborrheic dermatitis, and tinea versicolor. It has antifungal properties which can decrease Malassezia.
In addition, it can decrease cell turnover. Dandruff and seborrheic dermatitis both are characterized by increased cell turnover resulting in the buildup of dead skin cells, so selenium sulfide can benefit by decreasing scaliness and itchiness.
It is also one of the few ingredients that can disperse biofilms of fungi. As fungi grow, they can form a layer around them which can make them more resistant to antifungal ingredients. Selenium sulfide can disrupt this layer or film.
Shampoos with selenium sulfide have a beautiful orange color, but they don’t smell that good and the smell lingers on for a while even after rinsing the shampoo.
Concentration used
Selenium sulfide at a concentration of 1% is available over the counter while a 2.5% concentration is available only by prescription.
Side effects
Shampoos with selenium sulfide can lead to itching or burning sensation. Some people can experience increased oiliness of the scalp or hair. So, make sure to wash off the shampoo thoroughly when you use it.
It can discolor light-colored hair or fabrics. It can also stain metal jewelry.
Selenium sulfide and hair loss? We don’t have any solid evidence which suggests that it can directly cause hair loss.
Differences
Both these ingredients decrease Malassezia fungus by its antifungal properties.
In addition, selenium sulfide can reduce cell turnover which can benefit in decreasing layers of dead skin cells. Selenium sulfide can also disrupt the biofilm of fungi.
Theoretically, it makes selenium sulfide more effective in improving dandruff, seborrheic dermatitis, or tinea versicolor.
However, we don’t have much data or research studies where both these ingredients are compared directly. There is an older study from 1969 that found both 2% zinc pyrithione and 2.5% selenium sulfide formulation to be equally effective for dandruff.
Which one should you use?
Zinc pyrithione is often better tolerated than selenium sulfide. So, it may be a good choice for someone with a more sensitive scalp or dry hair.
If the smell of selenium sulfide shampoo is an issue, then zinc pyrithione shampoo is probably a better choice.
Zinc pyrithione may improve mild cases of dandruff, however for more resistant dandruff, selenium sulfide may be a better choice.
It also differs from person to person, how one’s skin condition responds to an ingredient or formulation.
Some people benefit from using more than one anti-dandruff ingredient in rotation.
How to use
No matter which shampoo you use, it is important to follow the directions of the product.
If there are no clear instructions, the following steps can help:
- Wet your hair.
- Lather your shampoo.
- Leave the lather on your scalp for 2-5 minutes.
- Rinse the shampoo well.
Leaving the shampoo on is important for anti-dandruff ingredients to work.
Dandruff shampoos with zinc pyrithione
- Vanicream Free & Clear Medicated Anti-Dandruff Shampoo – 2% zinc pyrithione (free of fragrance and sulfates) [Amazon] [Target]
- Dr. Eddie’s Happy Cappy Medicated Shampoo and Body Wash – 0.95% zinc pyrithione (free of fragrance and sulfates) [Amazon] [Walmart]
- DHS Zinc Dandruff Shampoo – 2% zinc pyrithione (contains fragrance, dyes, and sulfates) [Amazon] [Walmart]
Read more: Best Zinc Pyrithione Shampoos and How to Use Them
Dandruff shampoos with selenium sulfide
- Head & Shoulders Clinical Strength Dandruff Shampoo and Conditioner, Dry Scalp Rescue with Manuka Honey – 1% Selenium sulfide (contains sulfates, dyes, and fragrance) [Amazon] [Target]
- Selsun Blue Moisturizing with Aloe Dandruff Shampoo – 1% Selenium sulfide (contains sulfates, dyes, and fragrance) [Walmart] [Target]
- Selsun Blue 2-in-1 Anti-dandruff Shampoo & Conditioner – 1% Selenium sulfide (contains fragrance and sulfates) [Amazon] [Walmart]
Summary
With so many anti-dandruff shampoos, it becomes difficult to choose one. Zinc pyrithione and selenium sulfide are one of the most commonly found ingredients in dandruff shampoos.
While both are effective, if your dandruff is more resistant, selenium sulfide may be a better choice.
If the shampoo does not improve your scalp or skin condition, it’s best to see a doctor to get a prescription strength formulation.
Read more:
References
- Gilbertson K, Jarrett R, Bayliss SJ, Berk DR. Scalp discoloration from selenium sulfide shampoo: a case series and review of the literature. Pediatr Dermatol. 2012 Jan-Feb;29(1):84-8. doi: 10.1111/j.1525-1470.2011.01410.x. Epub 2011 Mar 31. PMID: 21453309.
- Ranganathan S, Mukhopadhyay T. Dandruff: the most commercially exploited skin disease. Indian J Dermatol. 2010 Apr-Jun;55(2):130-4. doi: 10.4103/0019-5154.62734. PMID: 20606879; PMCID: PMC2887514.
- Selenium sulfide. Mayo Clinic.
- Allen HB et al., Biofilm Formation by Malassezia Furfur/Ovale as a Possible Mechanism of Pathogenesis in Tinea Versicolor J Clin Exp Dermatol Res 2015, 6:6 DOI: 10.4172/2155-9554.10000311.
- Schwartz JR. Zinc Pyrithione: A Topical Antimicrobial With Complex Pharmaceutics. J Drugs Dermatol. 2016 Feb;15(2):140-4. PMID: 26885780.
- Orentreich N, Taylor EH, Berger RA, Auerbach R. Comparative study of two antidandruff preparations. J Pharm Sci. 1969 Oct;58(10):1279-80. doi: 10.1002/jps.2600581030. PMID: 4242482.
- Jo JH, Jang HS, Ko HC, Kim MB, Oh CK, Kwon YW, Kwon KS. Pustular psoriasis and the Kobner phenomenon caused by allergic contact dermatitis from zinc pyrithione-containing shampoo. Contact Dermatitis. 2005 Mar;52(3):142-4. doi: 10.1111/j.0105-1873.2005.00528.x. PMID: 15811028.
Disclaimer: This blog post is for information purposes only and does not replace medical advice.