FAQ - Pyrithione Zinc Bar Soap

What does DermaHarmony pyrithione zinc soap treat?

Seborrheic dermatitis and dandruff. We are prohibited from marketing our pyrithione zinc soap for any other uses. Folks use pyrithione zinc soap for a variety of other applications. Any off-label-drug-use (OLDU) should be managed by a medical professional.

Pyrithione Zinc is an active ingredient in our soaps. It is approved in concentrations from 0.3 to 3 percent when formulated to be applied and then washed away after brief exposure. It controls, fights, reduces, helps eliminate, helps stop, controls recurrence of, fights recurrence of, helps prevent recurrence of, reduces recurrence of, helps eliminate recurrence of, and helps stop recurrence of seborrheic dermatitis and dandruff. It helps with itching, irritation, redness, flaking, and scaling.

What fungi does pyrithione zinc kill?

Pyrithione zinc is a broad-spectrum antifungal agent. It is highly effective1 against:

  • Malassezia species like Malassezia globosa and Malassezia restricta, which cause dandruff and seborrheic dermatitis.
  • Aspergillus, a common mold found outdoors.
  • Trichophytos species, the fungi responsible for dermatophyte infections such as ringworm and athlete's foot.
  • Candida albicans, a yeast commonly found on the skin and mucous membranes (including thrush overgrowth).
  • Cryptococcus species, yeasts that cause serious infections in individuals with weakened immune systems).

Pyrithione zinc has been widely used for decades and yet there have been no reports of fungal resistance to pyrithione zinc in the same way as with other antifungal classes like azoles (e.g. ketoconazole). DermaHarmony products containing pyrithione zinc are only licensed for the treatment of dandruff and seborrheic dermatitis.  We provide this complete list of fungi for informational purposes only.

1 Source: A compilation of scholarly peer reviewed studies from 1960-2025.

What bacteria does pyrithione zinc kill?

The following bacteria have shown susceptibility2 to zinc pyrithione in scholarly peer reviewed studies and applications:

  • Staphylococcus aureus, a common gram-positive bacterium found on skin and in nasal passages. It can cause a range of infections, from mild skin infections to serious infections like pneumonia and sepsis.
  • Streptococcus agalactiae, a gram-positive bacterium that can cause infections like mastitis in livestock and can be associated with human infections.
  • Streptococcus dysgalactiae, a gram-positive streptococcus species linked to animal infections.
  • Escherichia coli (E. coli), a gram-negative bacterium commonly found in the intestines of humans and animals.
  • Pseudomonas aeruginosa, a gram-negative bacterium that can cause opportunistic infections, especially in individuals with compromised immune systems. It is often a concern in hospital settings and for wound infections.
  • Klebsiella pneumoniae, a gram-negative bacterium that can cause pneumonia and other infections.
  • Acinetobacter baumannii, a gram-negative bacterium that can cause severe infections in hospitalized patients which is known for its multi-drug resistance.
  • Enterococcus faecium, a gram-positive bacterium often found in the intestinal tract that can cause various infections, including urinary tract infections and bloodstream infections.
  • Enterococcus faecalis, a gram-positive enterococcus species that can cause similar infections to E. faecium.
  • Enterobacter cloacae, a gram-negative bacterium that can cause various infections, including respiratory tract and bloodstream infections.

While pyrithione zinc is effective against these bacteria in laboratory settings, its clinical efficacy in treating specific bacterial infections can vary depending on the severity of the infection, the specific bacteria type, and the formulation and application methods.  DermaHarmony products containing pyrithione zinc are only licensed for the treatment of dandruff and seborrheic dermatitis. We provide this complete list of bacteria for informational purposes only.

2 Source: A compilation of scholarly peer reviewed studies from 1960-2025.

Can pyrithione zinc kill cancer cells?

There is published peer-reviewed medical evidence that zinc pyrithione, used in a novel targeted approach, inhibits tumor growth and actually kills cancer cells. The detailed molecular mechanism of how this works remain unclear. We do not market DermaHarmony products for the treatment of cancer. At this time, pyrithione zinc is not an approved FDA active ingredient in any drug aimed at fighting cancer.

What happened to the old ZNP bar & brand?

Stiefel Laboratories stopped producing the "ZNP Bar" in 2010. We don't know why. The product was well liked by professionals in the medical community and the public. Stiefel Labs was acquired by GlaxoSmithKline in July 2009 to create a new specialist dermatology business. Glaxo, we gather by their actions, was uninterested in the soap business, likely due to lower margins and lots of competition. Availability of Stiefel Labs ZNP Bar ceased shortly after the acquisition.

Stiefel also discontinued SAStid (their Salicylic Acid and Sulfur soap), Acne-Aid, and their Sulfur Soap. PanOxyl (the BPO cleansing bar) went into short supply in 2012. Zeasorb was discontinued in the UK in 2013. The formula for the PanOxyl foaming wash was changed in 2018 leading to lots of consumer dissatisfaction. In 2024 (more than a decade later) the PanOxyl 10% BPO bar was re-introduced (similar to our formulation) after the brand was spun-off to Crown Laboratories.

DermaHarmony is not associated with Stiefel, Glaxo, or Crown. Many customers remember these brands and often ask for the DermaHarmony equivalents.

We love the medicated cleansing business and plan to make our products for many years to come. The DermaHarmony Pyrithione Zinc soap is similar to the original Stiefel Labs ZNP bar. Many customers of ours say that they like our soap as well or better than the original ZNP bar. Others say that they liked the original. Give us a try and let us know what you think!

How long do you leave the soap on your face? Do you apply and wash it off right away?

Lather your hands with the soap (no washcloth) and cover your face and do some lathering, then with comfortable warm water rinse thoroughly and pat dry with a clean towel. The zinc in that soap is strong but cleanses the pores well. 30-90 seconds is sufficient. Don't keep in contact with sensitive areas for longer. DermaHarmony Pyrithione Zinc Soap is safe to use every day.

What does the soap smell like?

The DermaHarmony zinc soap has no added fragrance. It smells like good old-fashioned soap - we struggle to find words when asked to describe the soap's smell. Everything smells like something, right? Most non-fragrance soaps, well, they smell like soap but are slightly unique to one another due to their different ingredients. The best answer is simple, clean, and organic-like. The smell is very slight. A faint scent and slight fragrance of what you would expect from a natural soap made from oils.

Does the soap contain any sulfates?

None of the DermaHarmony branded soap contains sulfates. We now have a second brand called Grace of Me the offers a wider range of cleansing products. Several of these new bars contain sulfates (e.g. Goat's Milk & Honey, Oatmeal, Lavender Flower soap). Others don't (e.g. African Black, Aloe-Cucumber-Bentonite-Clay). We're very cautious about how we use sulfates in these new products. None of the Grace of Me or DermaHarmony branded soaps or shampoo bars contain parabens, preservatives or PEG. The Grace of Me bars that are Sulfate Free are clearly marked so.

Can I use the bar soap as shampoo in my hair?

Yes.  We have thousands of customers that do so.  Notwithstanding, we think that our 2% Pyrithione Zinc Bar Shampoo by DermaHarmony or Grace of Me is a better option because it reacts better when used with 'hard water'.

Can I use the bar soap on my entire body?

In practice, the majority of our customers use pyrithione zinc as their only soap for their entire body. However, it's recommended to use it as a replacement for your regular soap only on affected areas and to follow the instructions on the product label. 

How long before I see results for Seborrheic Dermatitis?

You'll see results in 2-5 days if you wash your face daily.

What pH of the Zinc Therapy Bar Soap?

Our zinc bar soap consistently tests at a pH of 8.25. We quote a range of 9 to 9.5 pH, as testing methods can vary.

Is the oatmeal gluten free?

Yes, colloidal oatmeal (oats) is gluten-free.

Can this product be used on children?

Yes - it can be used on children under adult supervision.  Keep away from eyes. Zinc Pyrithione will irritate the eyes (flush eyes for several minutes if soap comes into contact).

Do the zinc soap bars lather?

This depends on the hardness of your tap water. The hardness of water is determined by the milligrams of calcium carbonateper litre and is reported it in parts-per-million or ppm. In general, water with less than 60ppm is soft. Water 60-120ppm is moderately hard.  Water with greater than 120ppm is hard.  The zinc bars lather well until 140ppm.

Can I use the soap in my ears?

Ears need to be washed regularly, so wash them with your zinc soap while you're sudsing up the rest of your face/body in the bath or shower. Try not to get water or soap deep into your ear canal. Most people actually never need to clean their ear canal. Ear canals are self-cleaning.

How to use zinc soap?

Lather your hands with the soap (no washcloth) and apply to affected areas. Leave in contact with skin for 30-90 seconds. Rinse with comfortable warm water and pat dry with a clean towel. This is safe for everyday use.

See our Pyrithione Zinc Bar Soaps: