Accession Number
Small Molecule

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].

  • 2-pyridinethiol 1-oxide
  • Omadine
  • Pyridinethiol N-oxide
External IDs
Product Ingredients
IngredientUNIICASInChI Key
Pyrithione sodium6L3991491R3811-73-2WNGMMIYXPIAYOB-UHFFFAOYSA-M
Pyrithione zincR953O2RHZ513463-41-7OTPSWLRZXRHDNX-UHFFFAOYSA-L
Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Dermazinc CreamCream2.5 mgTopicalDermalogix Partners, Inc.Not applicableNot applicableCanada
Dermazinc ShampooShampoo20 mgTopicalDermalogix Partners, Inc.Not applicableNot applicableCanada
Over the Counter Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
2 In 1Shampoo10.3 mg/1mLTopicalTARGET Corporation2013-05-06Not applicableUs
2 In 1Shampoo10.4 mg/1mLTopicalTARGET Corporation2013-05-16Not applicableUs
2 In 1Shampoo10.3 mg/1mLTopicalWal-Mart Stores, Inc2012-07-12Not applicableUs
2 In 1 Anti-dandruff Shampoo and ConditionerLotion1 %TopicalAvon Products, Inc.2003-10-092010-07-30Canada
2 in 1 AntidandruffShampoo10 mg/1mLTopicalApollo Health and Beauty Care Inc.2017-03-29Not applicableUs
2 In 1 Conditioning Dandruff ShampooShampoo1 %TopicalScott Chemical Canada2000-01-012005-09-16Canada
2 In 1 Conditioning Dandruff Treatment ShampooShampoo1 %TopicalAPOLLO HEALTH AND BEAUTY CARE2002-10-302011-07-07Canada
2 in 1 DandruffShampoo1 g/1mLTopicalH E B2016-10-19Not applicableUs
2 in 1 DandruffShampoo10 mg/1mLTopicalH.E.B.2009-05-15Not applicableUs
2 in 1 DandruffShampoo1 g/1mLTopicalFoodhold U.S.A.2016-12-06Not applicableUs
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing End
ActiprepPyrithione zinc (1 %) + Ethanol (83 %)LiquidTopicalHealthpoint2002-09-122004-07-13Canada
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
Add More HairPyrithione zinc (0.29 g/100mL) + Panthenol (0.5 g/100mL) + Salicylic acid (0.2 g/100mL)ShampooTopicalCoretree Co.,Ltd2017-03-012018-09-05Us
Anti Hair LossPyrithione zinc (2.1 g/100g) + Biotin (0.06 g/100g)SoapTopicalGolden B America, Llc.2018-03-13Not applicableUs
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
Bonogen hair care shampooPyrithione zinc (2.1 g/100g) + Biotin (0.06 g/100g) + Nadide (0.3 g/100g) + Panthenol (0.5 g/100g)ShampooTopicalBonogen Co., Ltd2010-03-01Not applicableUs
Bonogen Plus hair care shampooPyrithione zinc (2.1 g/100g) + Biotin (0.06 g/100g) + Nadide (0.3 g/100g) + Panthenol (0.6 g/100g)ShampooTopicalBonogen Co., Ltd2010-04-09Not applicableUs
Born HairPyrithione zinc (2.1 g/100g) + Biotin (0.06 g/100g) + Nadide (0.3 g/100g) + Panthenol (0.6 g/100g)ShampooTopicalBonogen Co., Ltd2010-04-09Not applicableUs
Carione RgPyrithione zinc (2.1 g/100mL) + Biotin (0.06 g/100mL) + Nicotinamide (0.3 g/100mL) + Panthenol (0.5 g/100mL)ShampooTopicalCell Activation Research Institute Co., Ltd2016-07-31Not applicableUs
D-COL Personal Hygiene Convenience kitPyrithione zinc (10 mg/1mL) + Chloroxylenol (2.4 mg/1mL)KitD-COL Inc2018-05-30Not applicableUs
CAS number
Average: 127.16
Monoisotopic: 127.009184959
Chemical Formula
InChI Key



Indicated for the treatment of dandruff and seborrheic dermatitis [2].

Associated Conditions

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].

Half life
Not Available
Not Available

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].

Affected organisms
  • Yeast and other fungi
Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
Not Available
Food Interactions
Not Available


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. [PubMed:21919897]
  2. Schwartz JR: Zinc Pyrithione: A Topical Antimicrobial With Complex Pharmaceutics. J Drugs Dermatol. 2016 Feb;15(2):140-4. [PubMed:26885780]
  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. [PubMed:21947398]
  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. [PubMed:28183164]
  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. [PubMed:16382685]
  6. Pyrithione zinc - National Library of Medicine HSDB Database - Toxnet [Link]
External Links
PubChem Compound
PubChem Substance
ATC Codes
D11AX12 — Pyrithione zinc
AHFS Codes
  • 84:28.00 — Keratolytic Agents
  • 84:04.92 — Miscellaneous Local Anti-infectives
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Clinical Trials

Clinical Trials
1CompletedBasic ScienceHealthy Volunteers3
1CompletedTreatmentDisseminated Sclerosis1
1, 2CompletedTreatmentAnterior Cruciate Ligament Injury / Osteoarthritis (OA)1
2CompletedTreatmentHigh Blood Pressure (Hypertension) / Type 2 Diabetes Mellitus1
3CompletedTreatmentAcute Urticaria1
3TerminatedSupportive CareCancer, Breast / Lung Cancers / Pain NOS1
4CompletedSupportive CareOral Lichen Planus1
4CompletedTreatmentSeasonal Allergic Rhinitis (SAR)1
Not AvailableCompletedNot AvailablePoisoning caused by organophosphorus pesticides1
Not AvailableCompletedNot AvailablePulmonary Embolism (PE) / Sinus Thrombosis, Intracranial / Thrombosis, Venous1
Not AvailableCompletedTreatmentOral Contraceptives (OC)1
Not AvailableRecruitingTreatmentAtopic Dermatitis (AD)1


Not Available
Not Available
Dosage forms
ShampooTopical1 g/1mL
ShampooTopical1.2 %
LotionTopical1 %
LotionTopical0.1 %
LotionTopical0.15 mL/150mL
ShampooTopical0.15 g/1mL
SoapTopical2 g/1000g
LotionTopical10 mg/1g
ShampooCutaneous0.01 mg/1mL
ShampooTopical1 mg/1mL
ShampooCutaneous10 mg/1mL
ShampooTopical0.05 g/100g
ShampooTopical2.0 %
ShampooTopical10 mg/1000mg
ShampooTopical20 mg/1mL
EmulsionTopical10 mg/1g
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 %
ShampooTopical1 g/100g
ShampooTopical5.7 g/285mL
ShampooTopical5.8 mg/290mL
GelTopical0.1 %
SuspensionTopical0.5 g/100mL
ShampooTopical1.0 g/100mL
LotionTopical0.0036 mg/1mL
LiquidTopical15 g/300mL
ShampooCutaneous3 g/300g
ShampooTopical2 %
ShampooTopical20 mg/1g
Lotion / shampooTopical1 kg/100kg
Lotion / shampooTopical1 g/100mL
ShampooTopical1 kg/100L
ShampooTopical1.9 g/100mL
ShampooTopical10.4 mg/1mL
ShampooTopical100 g/1mL
ShampooTopical9.5 mg/100mL
Shampoo, suspensionTopical958 mg/1mL
Lotion / shampooTopical1.0000 mL/100mL
SuspensionTopical0.5 %
Lotion / shampooTopical0.500 mL/100mL
CreamTopical1 %
ShampooTopical1.45 %
Lotion / shampooTopical1 kg/100L
SuspensionTopical1 %
LotionTopical1.0 %
SuspensionTopical1.0 %
GelTopical2.0 g/100mL
CreamTopical2.5 mg
ShampooTopical20 mg
SprayTopical2.5 mg
SolutionTopical0.95 g/100g
CreamTopical1 mg/1mL
LiquidTopical0.5 g/100mL
ShampooTopical14 mg/1mL
ShampooTopical1.2 g/100g
ShampooTopical12 g/1L
SolutionTopical2.4 mg/500mL
SolutionTopical0.09 g/100mL
ShampooTopical1.2 g/100mL
ShampooTopical10 mL/1000mL
ShampooTopical65.7 g/1000mL
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
ShampooTopical10 mg/10mL
ShampooTopical1 g/100mL
ShampooTopical1.008 g/100mL
ShampooTopical0.000048 g/100mL
ShampooTopical1.8 mg/300mL
ShampooTopical2 g/100mL
ShampooTopical3.84 mL/384mL
ShampooTopical7.5 mL/750mL
ShampooTopical12 mg/1mL
ShampooTopical2.5 g/250g
ShampooTopical1.68 %
ShampooTopical6 mg/300mL
ShampooTopical0.1 mL/100mL
SolutionTopical0.1 mL/100mL
ShampooTopical0.0095 g/1mL
ShampooTopical0.75 %
LotionTopical0.5 %
ShampooTopical0.5 %
CreamTopical0.75 %
Lotion / shampooTopical10 mg/1mL
LiquidTopical0.1 g/100mL
Lotion / shampooTopical0.5 g/1mL
LotionTopical5 mg/1mL
Lotion / shampooTopical2 g/100mL
Lotion / shampooTopical20 mg/1mL
Lotion / shampooTopical1 g/1mL
ShampooTopical0.01 g/1mL
LotionTopical0.5 mg/100mL
LotionTopical0.5 g/100mL
Lotion / shampooTopical.01 g/1mL
Lotion / shampooTopical0.01 g/1mL
CreamTopical0.1 g/100mL
CreamTopical0.5 g/100mL
LotionTopical0.1 g/100mL
LotionTopical1 g/100mL
Lotion / shampooTopical7.5 mg/1mL
ShampooTopical1.5 g/100g
ShampooTopical15 mg/1mL
EmulsionTopical1.0 g/100g
ShampooTopical15.4 g/1L
ShampooTopical10.3 mg/1mL
ShampooTopical1.0 g/100g
ShampooTopical1.8 %
LiquidTopical1 g/100mL
LotionTopical2 mg/1mL
ShampooTopical10 mg/1mL
ShampooTopical1.5 %
LiquidTopical2.1 g/100mL
ShampooTopical0.00336 g/1mL
ShampooTopical1 %
ShampooTopical5 mL/500mL
ShampooTopical0.3 mL/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
LotionTopical10 mg/1mL
ShampooTopical1.20000 mg/240mL
ShampooTopical10.5 mg/1mL
ShampooTopical2.52000 mg/240mL
ShampooTopical10.0 g/500mL
GelTopical0.48 g/100mL
Lotion / shampooTopical1 mg/1mL
LiquidTopical0.97 mg/1mL
Lotion / shampooTopical0.1 g/100mL
SolutionTopical0.1 %
CreamTopical1 mL/100mL
LiquidTopical1 %
LiquidTopical1.0 %
GelTopical2.0 g/100g
ShampooTopical4.04 g/400mL
Shampoo, suspensionTopical1 g/100mL
Shampoo, suspensionTopical0.45 mL/100mL
Shampoo, suspensionTopical1 mL/100mL
CreamTopical3 mg/1000mL
ShampooTopical1 mg/100mL
LiquidTopical29 mg/1mL
ShampooTopical2.41 g/237mL
GelTopical1 %
ShampooTopical1.0 %
ShampooCutaneous0.6 mL/360mL
ShampooTopical2.1 g/100mL
ShampooTopical1 mL/100mL
LiquidTopical10 mg/1mL
LiquidTopical1 mL/100mL
LiquidTopical1.0 mL/100mL
CreamTopical95 mg/1mL
ShampooTopical9.5 mg/1mL
SuspensionTopical0.95 %
ShampooTopical1.9 %
ShampooTopical0.95 %
ShampooTopical5 g/250g
ShampooTopical10 mg/1g
ShampooTopical3 mg/300mL
SolutionTopical0.95 g/100mL
AerosolTopical2 mg
ShampooTopical6 mg/1mL
ShampooTopical1 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
Lotion / shampooTopical1.2 g/1mL
ShampooTopical.01 g/.01g
RinseTopical.005 g/1g
RinseTopical5 mg/1mL
ShampooTopical10 g
ShampooTopical5 g/500g
CreamTopical250 mg/100g
LiquidTopical.15 %
LiquidTopical5 g/1000g
ShampooTopical2 g/100g
Lotion / shampooTopical20 mg/400mg
ShampooTopical20 mg/400mg
LiquidTopical2 g/100mL
SoapTopical2 g/100g
CreamTopical0.2 %
SprayTopical0.2 %
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
Not Available


Not classified

Drug created on September 14, 2010 10:21 / Updated on March 21, 2019 04:44