Anti-dandruff shampoo is one of the most popular shampoo categories, and often costs more than regular shampoo. Some of the leading anti-dandruff shampoo brands suggest that their products contain ingredients specifically formulated to treat dandruff.
But what actually causes dandruff and how is it best treated? Are there ingredients shown in medical studies to treat dandruff? Do anti-dandruff shampoos contain any unhealthy ingredients? And how do real users rate and describe the effects of popular anti-dandruff shampoos?
In this article we'll answer all of these questions and more as we review what causes dandruff and how it's best treated, and share results from medical studies on ingredients proven to have an anti-dandruff effect.
We'll also highlight some questionable additive ingredients in one of the most popular anti-dandruff shampoos, and feature real, unsponsored user reviews of popular anti-dandruff shampoo brands.
What Actually Causes Dandruff?
Dandruff is caused when seborrheic dermatitis affects skin on the scalp.
A 2015 medical review explains that dermatitis can affect any part of the body; it’s just called “dandruff” when it affects the scalp. It tends to be more noticeable on the scalp because the flaky dry skin can get caught in hair.
One of the main causes of dandruff is an overgrowth of a specific type of yeast on the skin called Malassezia. This yeast is a natural part of the skin ecosystem; it’s only a problem when its numbers increase beyond normal limits.
The strength of an individual's immune system and their genetics are also described in the above-linked review as factors that can increase likelihood of dandruff.
Given that dandruff is caused by localized inflammation and an overgrowth of a specific type of yeast, it seems logical that anti-inflammatory compounds and topical anti-fungals may be effective in its treatment.
A fascinating YouTube video published by the Wall Street Journal explains in more detail (with visual representations) what causes dandruff and how a popular formulation combats it:
Which Ingredients are Proven to Treat Dandruff?
A medical review published in the Indian Journal of Dermatology,highlighted some research-backed dandruff treatments.
Selenium sulfide is a topical antifungal medication that reduces levels of the yeast causing dandruff. It’s the active ingredient in many popular dandruff shampoo formulations like CVS Health Maximum Strength Dandruff Shampoo and Selsun Blue Medicated Antidandruff Shampoo.
As documented in the above-linked research study, selenium sulfide not only reduces levels of yeast on the scalp which cause dandruff, but also is proven to reduce cell turnover, which is a secondary benefit and can further reduce dandruff.
Pyrithione zinc is another ingredient which is proven to reduce dandruff when used topically. This is the active ingredient in Head & Shoulders Classic Clean Dandruff Shampoo.
A 1985 clinical trial found that pyrithione zinc shampoo reduced dandruff levels over time. The researchers also noted that there was a reduction in the level of various microorganisms on the scalp with use of the zinc shampoo.
A more recent medical study analyzed why pyrithione zinc was so effective against dandruff. It appears to have three mechanisms of action against the yeast which causes dandruff: it increases cellular zinc levels in the scalp, inhibits mitochondrial function of the yeast, and makes the scalp environment less favorable to growth of the yeast.
Individuals with dandruff may benefit from choosing shampoos with selenium sulfide or pyrithione zinc.
But how do real users rate and describe the effects of anti-dandruff shampoo? We'll review in the next section.
Real, Unsponsored Anti-Dandruff Shampoo User Reviews
A YouTube creator named "PoojaReviews" has a YouTube Short video sharing her rating and description of the effects of various anti-dandruff shampoo brands:
A YouTube creator named AngelZhane' shared her experience using one of the most popular anti-dandruff shampoos (Head & Shoulders):
Is Anti-Dandruff Shampoo Unhealthy?
The ingredients in Head & Shoulders Classic Clean Anti-Dandruff Shampoo are shown above.
This formulation contains several inactive ingredients that may be questionable from a health perspective.
Blue 1 and Red 33 are artificial dyes, and a medical review published in the Alternative Therapies in Health and Medicine journal found that artificial dye can absorb through the skin and may have toxic health effects in the human body.
Fragrance is clinically shown to have negative effects to human and environmental health, as we discussed in our review of Bounce Curl, a shampoo brand containing this ingredient.
Methylisothiazolinone and methylchloroisothiazolinone are synthetic preservatives which were shown to have toxic effects at concentrations as low as 16 parts per million (ppm) in a 2021 medical review.
Sodium benzoate is another synthetic preservative.
In our research for this article, we reviewed a number of commercial anti-dandruff shampoo formulations and found nearly all of them to contain questionable additive ingredients like the ones highlighted above.
But are there natural options for treating dandruff? We'll review in the next section.
Natural Anti-Dandruff Options
Coconut oil may be an effective natural anti-dandruff treatment.
A medical review on coconut oil for scalp health, published in the Scientific Reports journal, found that topical coconut oil application increased the levels of healthy bacteria in the scalp (Malassezia globosa), and reduced levels of harmful bacteria associated with dandruff formation (Malassezia restricta).
The study authors noted that coconut oil application also increased skin hydration on the scalp, which has an anti-dandruff effect.
Our top coconut oil brand is Dr. Bronner's Organic Virgin Coconut Oil, because it's packaged in glass, organic-certified, and free of unhealthy additive ingredients.
Interested consumers can check out Dr. Bronner's Organic Virgin Coconut Oil at this link to the product's official Amazon listing.
Fireweed (Epilobium angustifolium) extract is another promising natural alternative for treating dandruff.
A 2017 clinical trial found that fireweed extract at a concentration of 1.5% in a shampoo formulation reduced dandruff by over 50%, and the researchers concluded that this botanical extract offered “a new innovative approach to dandruff reduction.”
Our top fireweed extract product is Florida Herbal Pharmacy Fireweed Extract, because it's packaged in glass and free of unhealthy additive ingredients.
Consumers using this for dandruff should be aware that it needs to be diluted to be effective (remember that the concentration used in the clinical trial was only 1.5%).
Interested consumers can check out Florida Herbal Pharmacy Fireweed Extract at this link to the product's official Amazon listing.