Dandruff is one of the most common health concerns in the world today. It will affect over one out of two people at some point in their lives.
An active ingredient in many anti-dandruff shampoos is selenium sulfide. You can find this in popular brands like Head & Shoulders or Neutrogena.
Despite its popularity, there are long-standing concerns about this chemical’s toxicity. Of particular concern are the adverse effects on the skin, hair, and nails. One of the reported side effects is actually hair loss.
Are these concerns valid? Can using a selenium-sulfide shampoo actually damage your hair instead of restoring its health? Read on to find out.
What is Selenium Sulfide?
Selenium sulfide, also known as selenium disulfide, is an antifungal chemical compound (1). It is a common ingredient in hundreds of over-the-counter and prescription-strength antifungal treatments.
As the name suggests, the two component elements of selenium sulfide are selenium and sulfur.
You can find it in various forms including shampoo, cream, foam, lotion, and suspension. The 1% strength is over-the-counter. Higher strengths like 2.5% typically require a doctor’s prescription.
Selenium sulfide has been in use since the middle of the twentieth century (2). Since then, hundreds of millions of people all over the world have used selenium sulfide-containing products. Tens of thousands of doctors prescribe it to their patients every year.
Yet despite its popularity, there have been persistent questions regarding this chemical’s effect on human health (3). Aside from other safety concerns which we will discuss below, one potential side effect is hair loss.
Before this, however, let us first look at its primary indication: dandruff.
How Does It Work Against Dandruff?
All healthy people lose skin cells on their scalp and the rest of their body all the time, but these are normally not visible.
The white, ugly, crusty flakes we see in dandruff are actually a cluster of dead skin cells. For one reason or another, they retained a high degree of cohesion after dying (4). They then detached from the scalp in one solid chunk.
Scientists believe there are various causes of dandruff, but the most important is a fungus called Malassezia (5). This microorganism normally inhabits the scalp along with many other bacteria and fungi. In dandruff, however, it often multiplies out of control, essentially taking over the scalp from the other microorganisms.
Scientists do not exactly understand the mechanism through which Malassezia leads to the skin flaking. They also agree that other – mostly unknown – factors probably contribute to dandruff. What they do know with high confidence, however, is that getting Malassezia under control is one of the best strategies for treating dandruff (6).
As a potent anti-fungal, selenium sulfide can bring Malassezia under control. For this reason, it is a common ingredient in many popular dandruff-fighting shampoos, including:
- Selsun Blue
- Head & Shoulders
- Selsun Blue
- and many more
Aside from dandruff, selenium sulfide is also prescribed for the treatment of an associated condition, seborrheic dermatitis. It can help control the symptoms of this condition which include irritation, redness, and itching in the scalp.
Selenium Sulfide’s Effects on Health and Hair
For decades, researchers have noticed that selenium sulfide can adversely affect the skin and hair of certain individuals. Let’s have a closer look at these side effects.
In 2011, a team of physicians from St. Louis reported an intriguing series of case reports (7). A number of their child patients with seborrheic dermatitis presented with discoloration of the scalp after using selenium sulfide-containing shampoos. Their scalp had turned into a very unusual orange to brown color. You can see the photos here.
In all cases, once the children stopped using the shampoo, their scalp returned to its normal color.
Changes In Hair & Nail Color
In other cases, selenium sulfide use can directly change the color of the hair. Doctors have reported their patients’ hair taking a yellow or even green color after using selenium sulfide shampoos. This color can persist for several weeks or even months after the patients discontinue treatment (8, 9)
Other doctors have reported the nails of their patients changing color (10). This can happen when the patient uses selenium sulfide ointments to treat fungal skin conditions.
Other Side Effects
The scalp, hair, and nail changes we discussed above are rare. Most users of selenium sulfide products will not experience any issue like this.
Having said that, even if there are no visible changes, this does not mean selenium sulfide is having no effect. There is some evidence that high levels of exposure to selenium can have negative effects on neurological, hormonal, immune, and reproductive health. There have also been reports of adverse effects on the liver and teeth (11).
With regards to the skin, the most common adverse effect is contact dermatitis, namely redness, and itching.
What About Hair Loss?
Researchers agree that in sufficiently high levels, and especially in susceptible individuals, selenium can cause hair loss.
This is typically temporary and resolves after the patient is no longer exposed to the selenium. There are two ways this exposure can happen: through selenium sulfide shampoos and through occupational/environmental exposure.
An early study from 1960 found that even just one application of selenium sulfide had a negative effect on the hair roots of four subjects. Use of the shampoo led to increased damage (dysplasia) and hair loss (12).
All four subjects experienced increased levels of dysplasia 6, 9, and 12 days after the application of selenium sulfide shampoo.
For three of the four subjects, this increased dysplasia was evident as long as 68 days after application.
According to the authors of the study, a single-use was enough to damage the hair:
…changes in hair roots occurred when the selenium preparation is used only once in accordance with the manufacturers directions for use in controlling dandruff.
An even earlier study reported diffuse hair loss from six users of selenium-sulfide shampoos. In all cases, the hair loss ceased after the patients stopped the shampoo (13).
A subsequent study by Norman Orentreich, one of the most important dermatologists of the 20th century, failed to replicate these findings (14).
Orentreich and his team compared the hair of patients who used a selenium sulfide-containing suspension to those who used the same suspension without selenium sulfide. They found no difference between these two groups. This was the case after a single application as well as after prolonged exposure.
Certain parts of the world are naturally rich in selenium (“seleniferous”). For decades, researchers have noticed dermatologic problems – including hair loss – in residents of these areas. These include, among others:
- hair loss
- discoloration of the skin
- diseased fingernails
- depigmentation of the skin
These effects have been observed in parts of the world as diverse as the United States, Venezuela, and China. A study in a highly seleniferous part of Hubei Province in central China documented these side effects in detail (15).
Loss of hair and nails. The hair becomes dry and brittle and is easily broken off at the scalp. The appearance of a rash on the scalp is associated with intolerable itching. Usually hair can be removed by hard scratching. When hair is broken off, the [follicles] remain intact so that the hair continues to grow. Hair may also be lost from the brow, beard, arm pit and public hair. New hair is always depigmented and loses its luster; sometimes the ends are forked.
It is important to emphasize that a) these effects are common only after very high exposure to selenium and b) selenium sulfide is far less toxic than elemental (pure) selenium.
What Is the Consensus Today?
Since the 1960s, there has been surprisingly little research on the possible link between selenium sulfide shampoos and hair loss. In the meantime, however, the toxic effects of environmental selenium on the skin and hair have been abundantly documented.
As a result, medical sources today agree that temporary hair loss is a possible side effect of selenium sulfide shampoos. The patient information sheet lists this as a possible side effect, along with discoloration of the hair (16).
As the side effects of selenium are dose-dependent, the most important step you can take is to limit the duration of treatment. Your doctor will advise you on the optimal frequency and duration of use.
If you do notice excess hair loss while using a selenium sulfide shampoo, suspend use and immediately discuss this with your doctor.
Other Anti-Dandruff Medications
If you are struggling with dandruff but concerned about selenium sulfide’s adverse effect on your hair, there are plenty of other options to choose from.
Most of these anti-dandruff ingredients can control dandruff quite effectively, though typically they cannot eliminate it completely.
- salicylic acid
- coal tar
- zinc pyrithione
- ketoconazole (“Nizoral” shampoo).
You will find these ingredients in various anti-dandruff shampoos. Most of them are available without a prescription.
How to Know It’s Working
The first sign that your anti-dandruff shampoo is working is when the itching stops. At the same time, or very soon thereafter, the production of skin flakes drops, and the hair will soon look much healthier.
Since various anti-dandruff ingredients have different mechanisms of action, it might be a good idea to switch things up, cycling various shampoos. Your doctor will be able to advise you on this.
You will need to continue using anti-dandruff shampoos because two to three weeks after you stop, the numbers of Malassezia will often rebound and dandruff will reappear.
While over-the-counter and prescription treatments certainly have their place, there are natural ways to deal with dandruff and fungal infections of the scalp.
The scalp is its very own habitat, with its own ideal pH levels and nutrient requirements.
Its balance can be quickly thrown off, leading to skin irritation, flaking, fungal infections, and scalp buildup.
But what are the alternatives to selenium sulfide treatments when dealing with dandruff or other yeast-related maladies?
For those battling fungal infections, there are a few homemade treatment options – such as grapeseed oil and walnut oil– to test out.
Tea Tree Oil, Grape, and Black Walnut Fungal Treatment
With this three-ingredient fungal treatment, you can nourish your scalp and treat the fungal infection at the source – all without the use of harmful chemicals.
Combining equal parts of grapeseed oil with black walnut oil, and adding in 10 drops of tea tree oil, you can stir up your fungal treatment in a matter of minutes.
Apply the mixture directly to your scalp, prioritizing the most troublesome areas. You may leave in this mixture for up to 6 hours.
When ready to rinse, be sure to do so thoroughly with lukewarm (not hot!) water.
As mentioned, tea tree oil is a powerful antifungal. Grapeseed oil and walnut oil have their own curative properties as well. In addition to antifungal, grapeseed is also an antibacterial (17).
This means that scalp damage caused by bacterial infections, like folliculitis, can be treated with regular applications of grapeseed.
Walnut, interestingly, contains sterols. These are natural inhibitors of 5-alpha-reductase and can reduce inflammation of the scalp.
Since Malassezia thrives on oily skin, you will probably see an improvement in symptoms by removing excess oil from the scalp.
This means that even if you don’t want to use a medicated anti-dandruff shampoo, you will benefit from regular shampooing, as it will remove the excess oil from the scalp.
Other possible dandruff triggers include the sun, hard brushing, over-shampooing, and unidentified airborne chemicals in the environment. Limiting your exposure to these triggers may also keep dandruff under control. In some people, dandruff can also flare up with stress.
While selenium sulfide is a common ingredient in dandruff shampoos, there is evidence to suggest a link with hair loss, at least in higher dosages.
For individuals with thick hair, this side effect may not be an issue. For those with male-pattern baldness, however, excess hair loss is the last complication they want to be dealing with.
So, should you avoid selenium sulfide?
If you are reading this site, you likely suffer from one degree of hair loss or another. Since there are so many other options for treating dandruff, it makes sense to avoid selenium sulfide altogether.
If you do decide to use a selenium sulfide shampoo, you should consider using it for a limited period of time only. In consultation with your doctor, you can develop the anti-dandruff regimen that works best for your needs.
If you notice any changes to your skin, nails, or hair on the rest of the body while using a selenium sulfide shampoo, report these to your doctor immediately.