Pyrithione is an antimicrobial agent used for the treatment of dandruff and seborrheic dermatitis.

Brand Names
Generic Name
DrugBank Accession Number

Pyrithione zinc, or zinc pyrithione or zinc pyridinethione, is a coordination complex consisted of pyrithione ligands chelated to zinc (2+) ions via oxygen and sulfur centers. In the crystalline state, it exists as a centrosymmetric dimer. Due to its dynamic fungistatic and bacteriostatic properties, pyrithione zinc is used to treat dandruff and seborrheic dermatitis. Dandruff is a common scalp disease affecting >40% of the world's adult population, and may be caused by fungi such as Malassezia globosa and M. restricta 3.

Pyrithione zinc is commonly found as an active ingredient in OTC antidandruff topical treatments such as shampoos. It mediates its action by increasing the cellular levels of copper, and damaging iron-sulfur clusters of proteins essential for fungal metabolism and growth 1. Due to low solubility, pyrithione zinc released from the topical formulations is deposited and retained relatively well onto the target skin surfaces 2. Other uses of pyrithione zinc include additive in antifouling outdoor paints and algaecide. While its use has been approved in the early 1960's by the FDA 4, safety and effectiveness of pyrithione zinc has been reported for decades. It is not shown to have any significant estrogenic activity according to the in vivo and in vitro assays 4.

Small Molecule
Average: 127.16
Monoisotopic: 127.009184959
Chemical Formula
  • 2-pyridinethiol 1-oxide
  • Omadine
  • Pyridinethiol N-oxide
External IDs
  • NSC-290409



Indicated for the treatment of dandruff and seborrheic dermatitis 2.

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Associated Conditions
Indication TypeIndicationCombined Product DetailsApproval LevelAge GroupPatient CharacteristicsDose Form
Used in combination to treatDandruffCombination Product in combination with: Ketoconazole (DB01026)•••••••••••••••••••
Symptomatic treatment ofDandruff••• •••
Used in combination to treatSeborrheic dermatitisCombination Product in combination with: Ketoconazole (DB01026)•••••••••••••••••••
Symptomatic treatment ofSeborrheic dermatitis••• •••
Contraindications & Blackbox Warnings
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Pyrithione zinc has a broad antimicrobial spectrum of activity, including fungi, gram-positive and gram-negative bacteria 2. Pyrithione zinc is effective against Malassezia and all other fungi, especially the Malassezia species found on scalp 5. In patients with dandruff, treatment with pyrithione zinc reduced the amount of fungus on the scalp, which reduces the amount of free fatty acids, thereby reducing scalp flaking and itch 5.

Mechanism of action

Inhibition of fungal growth by pyrithione zinc is linked to increased copper uptake and cellular levels of copper, which is demonstrated by decreased CTR1-lacZ expression and slightly increased CUP1-lacZ expression in affected microorganisms 3. The coordination complex of pyrithione zinc dissociates, and pyrithione ligand forms a CuPT complex from available extracellular copper in the target organism. Pyrithione acts as an ionophore, interacting nonspecifically with the plasma membrane to shuttle copper into the cell, and facilitates copper transport across intracellular membranes 3. Copper may be shuttled into the mitochondria. Copper inactivates iron-sulfur (Fe-S) cluster-containing proteins via a mechanism similar to that described for copper-induced growth inhibition in bacteria 3. Decreased activity of Fe-S proteins leads to inhibition of fungal metabolism and fungal growth. Pyrithione zinc has been shown to slightly increase the levels of zinc 3.


Following oral ingestion, only the pyrithione moiety is absorbed. Less than 1% of administered zinc pyrithione is absorbed from the skin 6. Radioabeled Zn pyrithione administered to rats, rabbits and monkeys, either orally or via intraperitoneal injection were absorbed into circulatin to extent of 80-90% 6.

Volume of distribution

Not Available

Protein binding

Not Available


After oral administration in rabbits, rats, monkeys, and dogs, pyrithione zinc is biotransformed into 2-pyridinethiol 1-oxide S-glucuronide and 2-pyridinethiol S-glucuronide 6.

Route of elimination

The major route of elimination from the body after oral administration in rat was urine, with S-glucuronides of 2-mercaptopyridine-N-oxide being the major metabolites and 2-mercaptopyridine-N-oxide as the minor metabolite. Following oral administration, the majority of zinc is eliminated in the feces 6. Upon dermal administration, >90% of recovery was obtained from washings of the application site of pigs. Urinary excretion was 3% in animals with intact skin 6.


Not Available


Not Available

Adverse Effects
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Acute oral LD50 value is 177 mg/kg in rat and 160 mg/kg in mouse. Acute dermal LD50 was 100 mg/kg in rabbit MSDS.

Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
Tenofovir alafenamideThe serum concentration of Tenofovir alafenamide can be increased when it is combined with Pyrithione.
Food Interactions
No interactions found.


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Product Ingredients
IngredientUNIICASInChI Key
Pyrithione sodium6L3991491R3811-73-2WNGMMIYXPIAYOB-UHFFFAOYSA-M
Pyrithione zincR953O2RHZ513463-41-7OTPSWLRZXRHDNX-UHFFFAOYSA-L
Over the Counter Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
111MedCo Medicated Bar 2 Pyrithione ZincSoap20 mg/1gTopical111MedCo LLC2023-10-01Not applicableUS flag
2 In 1Shampoo10.4 mg/1mLTopicalTARGET Corporation2013-05-16Not applicableUS flag
2 In 1Shampoo10.3 mg/1mLTopicalTARGET Corporation2013-05-06Not applicableUS flag
2 In 1Shampoo10.3 mg/1mLTopicalWal-Mart Stores, Inc2012-07-12Not applicableUS flag
2 In 1Shampoo10 mg/1mLTopicalLidl Us Llc2021-08-12Not applicableUS flag
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
574H Cell CarePyrithione zinc (3.0 g/300mL) + Biotin (0.18 g/300mL) + Nicotinamide (0.9 g/300mL) + Panthenol (1.5 g/300mL)ShampooTopicalCelino Inc.2020-06-01Not applicableUS flag
ActiprepPyrithione zinc (1 %) + Ethanol (83 %)LiquidTopicalHealthpoint2002-09-122004-07-13Canada flag
Add More HairPyrithione zinc (0.28 g/100mL) + Panthenol (0.5 g/100mL) + Salicylic acid (0.2 g/100mL)ShampooTopicalCoretree Co.,Ltd2018-06-092018-09-05US flag
Add More HairPyrithione zinc (0.29 g/100mL) + Panthenol (0.5 g/100mL) + Salicylic acid (0.2 g/100mL)ShampooTopicalCoretree Co.,Ltd2017-03-012018-09-04US flag
Anti Hair LossPyrithione zinc (2.1 g/100g) + Biotin (0.06 g/100g)SoapTopicalGolden B America, Llc.2018-03-13Not applicableUS flag
Unapproved/Other Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
574H Cell CarePyrithione zinc (3.0 g/300mL) + Biotin (0.18 g/300mL) + Nicotinamide (0.9 g/300mL) + Panthenol (1.5 g/300mL)ShampooTopicalCelino Inc.2020-06-01Not applicableUS flag
Add More HairPyrithione zinc (0.29 g/100mL) + Panthenol (0.5 g/100mL) + Salicylic acid (0.2 g/100mL)ShampooTopicalCoretree Co.,Ltd2017-03-012018-09-04US flag
Add More HairPyrithione zinc (0.28 g/100mL) + Panthenol (0.5 g/100mL) + Salicylic acid (0.2 g/100mL)ShampooTopicalCoretree Co.,Ltd2018-06-092018-09-05US flag
Anti Hair LossPyrithione zinc (2.1 g/100g) + Biotin (0.06 g/100g)SoapTopicalGolden B America, Llc.2018-03-13Not applicableUS flag
Bonnoir Hair MediPyrithione zinc (7.35 mL/350mL) + Biotin (0.21 mL/350mL) + Nicotinamide (1.05 mL/350mL) + Panthenol (1.75 mL/350mL)ShampooTopicalCellinbio Co Ltd2011-07-27Not applicableUS flag


ATC Codes
D11AX12 — Pyrithione zinc
Drug Categories
Not classified
Affected organisms
  • Yeast and other fungi

Chemical Identifiers

CAS number
InChI Key


Synthesis Reference

Schwartz JR: Zinc Pyrithione: A Topical Antimicrobial With Complex Pharmaceutics. J Drugs Dermatol. 2016 Feb;15(2):140-4.

General References
  1. Reeder NL, Xu J, Youngquist RS, Schwartz JR, Rust RC, Saunders CW: The antifungal mechanism of action of zinc pyrithione. Br J Dermatol. 2011 Oct;165 Suppl 2:9-12. doi: 10.1111/j.1365-2133.2011.10571.x. [Article]
  2. Schwartz JR: Zinc Pyrithione: A Topical Antimicrobial With Complex Pharmaceutics. J Drugs Dermatol. 2016 Feb;15(2):140-4. [Article]
  3. Reeder NL, Kaplan J, Xu J, Youngquist RS, Wallace J, Hu P, Juhlin KD, Schwartz JR, Grant RA, Fieno A, Nemeth S, Reichling T, Tiesman JP, Mills T, Steinke M, Wang SL, Saunders CW: Zinc pyrithione inhibits yeast growth through copper influx and inactivation of iron-sulfur proteins. Antimicrob Agents Chemother. 2011 Dec;55(12):5753-60. doi: 10.1128/AAC.00724-11. Epub 2011 Sep 26. [Article]
  4. Yoon KS, Youn N, Gu H, Kwack SJ: Estrogenic activity of zinc pyrithione: an in vivo and in vitro study. Environ Health Toxicol. 2017 Feb 9;32:e2017004. doi: 10.5620/eht.e2017004. eCollection 2017. [Article]
  5. DeAngelis YM, Gemmer CM, Kaczvinsky JR, Kenneally DC, Schwartz JR, Dawson TL Jr: Three etiologic facets of dandruff and seborrheic dermatitis: Malassezia fungi, sebaceous lipids, and individual sensitivity. J Investig Dermatol Symp Proc. 2005 Dec;10(3):295-7. doi: 10.1111/j.1087-0024.2005.10119.x. [Article]
  6. Pyrithione zinc - National Library of Medicine HSDB Database - Toxnet [Link]
  7. NPRA Product Information: Dezor Plus (zinc pyrithione/ketoconazole) topical shampoo [Link]
PubChem Compound
PubChem Substance
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Clinical Trials

Clinical Trials
Clinical Trial & Rare Diseases Add-on Data Package
Explore 4,000+ rare diseases, orphan drugs & condition pairs, clinical trial why stopped data, & more. Preview package
PhaseStatusPurposeConditionsCountStart DateWhy Stopped100+ additional columns
4CompletedTreatmentHyperpigmentation1somestatusstop reasonjust information to hide
4RecruitingTreatmentAtopic Dermatitis1somestatusstop reasonjust information to hide
4Unknown StatusTreatmentQuality of Life (QOL) / Seborrheic Dermatitis1somestatusstop reasonjust information to hide
3TerminatedTreatmentAtrophic Vaginitis1somestatusstop reasonjust information to hide
0CompletedBasic ScienceRosacea1somestatusstop reasonjust information to hide


Not Available
Not Available
Dosage Forms
SoapTopical20 mg/1g
ShampooTopical10.3 mg/1mL
ShampooTopical1.2 %
LotionTopical0.1 % w/w
LotionTopical0.15 mL/150mL
ShampooTopical0.15 g/1mL
SoapTopical2 g/1000g
CreamTopical0.12 g/100mL
LotionTopical2.1 g/100mL
SolutionTopical20 mg/1mL
ShampooCutaneous0.01 mg/1mL
ShampooCutaneous10 mg/1mL
ShampooTopical0.05 g/100g
ShampooTopical10 mg/100mL
ShampooTopical2.0 %
ShampooTopical1 % w/v
ShampooTopical10 mg/1000mg
ShampooTopical20 mg/1mL
EmulsionTopical10 mg/1g
ShampooTopical10 mg/1mL
LotionTopical2.14 mg/1mL
ShampooTopical2.14 mg/1mL
ShampooTopical10.32 mg/1mL
CreamTopical2.14 mg/1mL
LiquidTopical0.2 %
ShampooTopical10.2 mg/1mL
LiquidTopical10.2 mg/1mL
LiquidTopical4.9 mg/1mL
CreamTopical0.2 g/100g
Liquid; shampooTopical1 %
ShampooTopical2.3 g/230g
ShampooTopical1.05 g/100mL
Lotion / shampooTopical.1 g/10g
Lotion / shampooTopical.5 g/10g
Lotion / shampooTopical1 g/10g
ShampooTopical4.5 mL/300mL
SprayTopical0.19 mg/1mL
CreamTopical0.2 mg/1g
CreamTopical0.2 mg/1mL
CreamTopical.1 %
GelTopical0.95 g/100mL
ShampooTopical5.7 g/285mL
ShampooTopical5.8 mg/290mL
GelTopical0.1 %
ShampooTopical1000 mg/100mL
SuspensionTopical0.5 g/100mL
ShampooTopical1.0 g/100mL
SolutionTopical0.1 % w/w
Shampoo, suspensionTopical20 mg/1mL
ShampooTopical0.5 g/100mL
LotionTopical0.0036 mg/1mL
LiquidTopical15 g/300mL
Kit; shampoo; soapTopical
ShampooTopical0.003 g/1mL
ShampooCutaneous3 g/300g
ShampooTopical2 %
LotionTopical10 mg/1g
ShampooTopical20 mg/1g
ShampooTopical1 mg/1mL
ShampooTopical1 kg/100L
ShampooTopical1.0 % w/w
ShampooTopical1.9 g/100mL
ShampooTopical10.0 mg/100mL
ShampooTopical10.4 mg/1mL
ShampooTopical100 g/1mL
Shampoo, suspensionTopical958 mg/1mL
Lotion / shampooTopical1.0000 mL/100mL
SuspensionTopical0.5 % w/w
Lotion / shampooTopical0.500 mL/100mL
CreamTopical1 % w/w
CreamTopical1 %
ShampooTopical1.45 %
Lotion / shampooTopical1 kg/100L
SuspensionTopical1 %
LotionTopical1 % w/w
LotionTopical1.0 % w/w
SuspensionTopical1.0 %
GelTopical2.0 g/100mL
SoapTopical1 g/100g
CreamTopical0.25 g/100mL
CreamTopical0.25 g/100g
SprayTopical0.25 g/100mL
CreamTopical2.5 mg / g
ShampooTopical20 mg / g
SprayTopical0.25 %
ShampooTopical1.65 g/100ml
SolutionTopical0.95 g/100g
CreamTopical1 mg/1mL
LiquidTopical0.5 g/100mL
ShampooTopical2.4 g/500g
ShampooTopical14 mg/1mL
ShampooTopical1.2 g/100g
ShampooTopical12 g/1L
CreamTopical2 g/100mL
SolutionTopical2.4 mg/500mL
SolutionTopical0.09 g/100mL
ShampooTopical1.2 g/100mL
ShampooTopical10 mL/1000mL
ShampooTopical65.7 g/1000mL
ShampooTopical300 mg/100mL
LiquidTopical3 mg/1mL
LiquidTopical0.05 g/1mL
ShampooTopical5.28 mg/1mL
LiquidTopical0.0036 mg/1mL
LiquidTopical0.00528 g/1mL
LiquidTopical0.011 mg/1mL
LiquidTopical0.0034 mg/1mL
ShampooTopical1.0 g / 100 g
ShampooTopical10 mg/10mL
ShampooTopical1 g/100mL
Lotion / shampooTopical0.02 kg/1kg
ShampooTopical0.000048 g/100mL
ShampooTopical1.008 g/100mL
ShampooTopical1.8 mg/300mL
ShampooTopical2 g/100mL
ShampooTopical1 kg/100kg
ShampooTopical12 mg/1mL
ShampooTopical2.5 g/250g
LotionTopical1 %
ShampooTopical1.68 %
ShampooTopical6 mg/300mL
ShampooTopical6.4 g/320mL
ShampooTopical0.1 mL/100mL
SolutionTopical0.1 mL/100mL
ShampooTopical0.0095 g/1mL
ShampooTopical0.75 % w/w
ShampooTopical0.5 %
ShampooTopical0.5 % w/w
CreamTopical0.75 % w/w
Lotion / shampooTopical0.01 mg/1mg
Lotion / shampooTopical10 mg/1mL
LotionTopical0.75 g/100mL
CreamTopical0.2 g/100mL
LotionTopical0.2 g/100mL
LiquidTopical0.1 g/100mL
Lotion / shampooTopical0.5 g/1mL
LotionTopical0.5 g/100mL
LotionTopical5 mg/1mL
Kit; lotion; shampooTopical
Kit; lotion; lotion / shampooTopical
Lotion / shampooTopical2 g/100mL
Lotion / shampooTopical20 mg/1mL
PasteTopical0.1 g/100g
Lotion / shampooTopical1 g/1mL
ShampooTopical0.01 g/1mL
LotionTopical0.5 mg/100mL
Lotion / shampooTopical1 g/100mL
Lotion / shampooTopical.01 g/1mL
Lotion / shampooTopical0.01 g/1mL
CreamTopical0.1 g/100mL
CreamTopical0.5 g/100mL
LotionTopical0.1 g/100g
LotionTopical0.1 g/100mL
LotionTopical1 g/100mL
OilTopical0.5 g/100mL
CreamTopical0.1 g/100g
GelTopical0.1 g/100mL
CreamTopical1 g/100mL
Lotion / shampooTopical7.5 mg/1mL
ShampooTopical1.5 g/100g
ShampooTopical15 mg/1mL
EmulsionTopical1.0 g/100g
ShampooTopical15.4 g/1L
ShampooTopical0.1 % w/w
ShampooTopical1.1 g/100g
ShampooTopical1.0 g/100g
ShampooTopical1.8 %
LiquidTopical1 g/100mL
LotionTopical2 mg/1mL
ShampooTopical1.5 %
LiquidTopical2.1 g/100mL
ShampooTopical0.00336 g/1mL
ShampooTopical1 %
ShampooTopical0.3 mg/100mL
ShampooTopical0.3 g/100mL
ShampooTopical.01 g/1g
Shampoo, suspensionTopical.01 g/1g
ShampooTopical1.8 g/100mL
ShampooTopical15.0 g/1.0L
ShampooTopical3.0 g/300g
ShampooTopical1.008 g / 100 g
LotionTopical10 mg/1mL
ShampooTopical1.20000 mg/240mL
ShampooTopical10.5 mg/1mL
ShampooTopical2.52000 mg/240mL
ShampooTopical1 g/100g
ShampooTopical0.2 % w/w
ShampooTopical10.0 g/500mL
ShampooTopical1.5 g/500mL
GelTopical0.48 g/100mL
Lotion / shampooTopical1 mg/1mL
LiquidTopical0.97 mg/1mL
Lotion / shampooTopical0.1 g/100mL
SolutionTopical0.1 %
CreamTopical1 mL/100mL
ShampooTopical1 g/1mL
LiquidTopical20 mg/1mL
LiquidTopical1 %
LiquidTopical1.0 %
GelTopical2.0 g/100g
ShampooTopical4.04 g/400mL
Shampoo, suspensionTopical1 g/100mL
Shampoo, suspensionTopical0.45 mL/100mL
Shampoo, suspensionTopical1 mL/100mL
LotionTopical0.5 % w/w
ShampooTopical1 mg/100mL
CreamTopical3 mg/1000mL
LiquidTopical29 mg/1mL
ShampooTopical2.41 g/237mL
GelTopical1 % w/w
ShampooTopical1.0 %
ShampooCutaneous0.6 mL/360mL
ShampooTopical2.1 g/100mL
ShampooTopical1 mL/100mL
LiquidTopical10 mg/1mL
LiquidTopical1 mL/100mL
LiquidTopical1.0 mL/100mL
CreamTopical9.5 mg/1mL
ShampooTopical0.95 %
ShampooTopical1.9 %
ShampooTopical0.95 % w/w
ShampooTopical9.5 mg/1mL
ShampooTopical5.0 g/500mL
ShampooTopical1 % w/w
ShampooTopical5 g/250g
ShampooTopical10 mg/1g
ShampooTopical3 mg/300mL
SolutionTopical0.95 g/100mL
AerosolTopical2 mg / mL
ShampooTopical0.3 % w/w
ShampooTopical6 mg/1mL
ShampooTopical1 g / 100 g
SuspensionTopical0.25 %
ShampooTopical0.5 mL/100mL
ShampooTopical1.0 mL/100mL
SuspensionTopical0.5 mL/100mL
CreamTopical1 mg/1g
Shampoo, suspensionTopical10 mg/1mL
LotionTopical1 mg/1mL
CreamTopical0.1 % w/w
Lotion / shampooTopical1.2 g/1mL
ShampooTopical.01 g/.01g
RinseTopical.005 g/1g
RinseTopical1 g/100mL
RinseTopical5 mg/1mL
CreamTopical0.125 g/100mL
ShampooTopical10 g / kg
ShampooTopical2 % w/w
SoapTopical2 g/100g
ShampooTopical5 g/500g
CreamTopical250 mg/100g
LiquidTopical.15 %
Lotion / shampooTopical300 mg/100mL
LiquidTopical5 g/1000mL
ShampooTopical2 g/100g
Lotion / shampooTopical20 mg/400mg
ShampooTopical20 mg/400mg
ShampooTopical2.98 g/300mL
SuspensionTopical2 %
GelTopical1 g/100g
ShampooTopical20 mg/2mL
LiquidTopical2 g/100mL
CreamTopical0.2 %
SprayTopical0.2 %
SuspensionTopical100 g
SoapTopical0.020 g/1
SoapTopical2 %
CreamTopical.5 %
Not Available
Not Available


Experimental Properties
boiling point (°C)100 (Zinc salt)MSDS
water solubilitySoluble in cold water (Zinc salt)MSDS
Predicted Properties
Water Solubility3.0 mg/mLALOGPS
pKa (Strongest Acidic)6.84Chemaxon
pKa (Strongest Basic)0.66Chemaxon
Physiological Charge-1Chemaxon
Hydrogen Acceptor Count1Chemaxon
Hydrogen Donor Count1Chemaxon
Polar Surface Area26.94 Å2Chemaxon
Rotatable Bond Count0Chemaxon
Refractivity34.48 m3·mol-1Chemaxon
Polarizability12.19 Å3Chemaxon
Number of Rings1Chemaxon
Rule of FiveYesChemaxon
Ghose FilterNoChemaxon
Veber's RuleYesChemaxon
MDDR-like RuleNoChemaxon
Predicted ADMET Features
Not Available


Mass Spec (NIST)
Not Available
SpectrumSpectrum TypeSplash Key
Predicted 1H NMR Spectrum1D NMRNot Applicable
Predicted 13C NMR Spectrum1D NMRNot Applicable
Chromatographic Properties
Collision Cross Sections (CCS)
Not Available

Drug created at September 14, 2010 16:21 / Updated at July 19, 2024 10:02