p-Hydroxyanisole
AKA “4-Methoxyphenol, Mequinol, p-Methoxyphenol, Phenol, HYDROQUINONE MONOMETHYL ETHER, MEHQ, Leucobasal”
Synthetic
Ingredient Facts
p-Hydroxyanisole
AKA: 4-Methoxyphenol, Mequinol, P-Methoxyphenol, Phenol, HYDROQUINONE MONOMETHYL ETHER, MEHQ, Leucobasal
Synthetic · Antioxidant · EWG: 4
Synthetic
Antioxidant
Anti-Aging
Barrier Support
Synthetic
Clean
A stabilizing antioxidant that helps protect formulas from oxidation and degradation, keeping products fresh and effective longer.
Solubility Soluble (NTP, 1992)
Formula
C7H8O2
Mol. Weight
124.14
CAS #
150-76-5
Form
Powder
State
Hydroquinone monomethyl ether appears as pink crystals or white waxy solid. (NTP, 1992)
See origin →
Functions
Antioxidant
Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.
Reducing
Anti-Aging
Targets fine lines, wrinkles, or loss of firmness. Works by boosting collagen, speeding cell turnover, or both.
Skin Protecting
Helps rebuild and strengthen your skin barrier — the invisible shield that keeps moisture in and irritants out. Essential after over-exfoliating or harsh weather.
Neutralizes Free Radicals
Traditional Use
A synthetic aromatic compound developed in the 20th century as a preservative and fragrance component. Used in cosmetics as an antioxidant and skin-conditioning agent in modern formulations.
Skin Types
●all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
No
EWG
4
CIR
Unsafe
Pregnancy
No
Restricted By
CIR Safety Findings
medical-approval
all-shades-safe
Concentration Guide
0.02%
0%0%
Reg. Limit
EU regulatory limit: 0.02%. For professional use only Avoid skin contact Read directions for use carefully Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 95.
Regulatory Agencies
2-Amino-4-nitrophenol.
IARC monographs on the evaluation of carcinogenic risks to humans, 1993
2-Amino-5-nitrophenol.
IARC monographs on the evaluation of carcinogenic risks to humans, 1993
4-amino-2-nitrophenol.
IARC monographs on the evaluation of the carcinogenic risk of chemicals to man, 1978
Polyphenols: skin photoprotection and inhibition of photocarcinogenesis.
Afaq F, Katiyar SK
Mini reviews in medicinal chemistry, 2011
Polyphenols: skin photoprotection and inhibition of photocarcinogenesis.
Afaq F, Katiyar SK
Mini reviews in medicinal chemistry, 2011
Potential skin anti-aging effects of main phenolic compounds, tremulacin and tremuloidin from Salix chaenomeloides leaves on TNF-α-stimulated human de
Ahn SY, Kim KA, Lee S, Kim KH
Chemico-biological interactions, 2024
Efficacy of a topical polyphenol-based formulation in palmoplantar psoriasis: an observational study.
Amato S, Dattola A, Bennardo L, Tolone M, Nisticò SP
Dermatology reports, 2025
Efficacy of a topical polyphenol-based formulation in palmoplantar psoriasis: an observational study.
Amato S, Dattola A, Bennardo L, Tolone M, Nisticò SP
Dermatology reports, 2025
Final report on the safety assessment of amino nitrophenols as used in hair dyes.
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
Final report on the safety assessment of amino nitrophenols as used in hair dyes.
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
Final report on the safety assessment of amino nitrophenols as used in hair dyes.
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
Final Amended Report on the Safety Assessment of p-Methylaminophenol Sulfate and p-Methylaminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of 2-Amino-6-Chloro-4-Nitrophenol and 2-Amino-6-Chloro-4-Nitrophenol Hydrochloride
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of 2-Methyl-5-Hydroxyethylaminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of 2,4-Diaminophenol and 2,4-Diaminophenol Dihydrochloride
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of 6-Amino-m-Cresol, 6-Amino-o-Cresol, 4-Amino-m-Cresol, 5-Amino-4-Chloro-o-Cresol, 5-Amino-6-Chloro-o-Cresol and 4-Chloro-2-Aminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Amino Nitrophenols Used in Hair Dyes
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of p-Aminophenol, m-Aminophenol, and o-Aminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of p-Hydroxyanisole
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of p-Methylaminophenol Sulfate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report on the Safety Assessment of Zinc Phenolsulfonate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report: Amended Safety Assessment of 4-Chloro-2-Aminophenol as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report: Amended Safety Assessment of p-Hydroxyanisole as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report: Safety Assessment of Sodium Benzotriazolyl Butylphenol Sulfonate as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Final Report: Safety Assessment of Tetrabromophenol Blue as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Re-evaluation: p-Hydroxyanisole
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
Zinc Phenolsulfonate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
2-Amino-6-Chloro-4-Nitrophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
2-Methyl-5-Hydroxyethylaminophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
3-Nitro-p-Hydroxyethylaminophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
4-Amino-3-Nitrophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
4-Hydroxypropylamino-3-Nitrophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
p-Hydroxyanisole
European Commission
EU Cosmetic Ingredient Database (CosIng)
Sodium Benzotriazolyl Butylphenol Sulfonate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Zinc Phenolsulfonate
European Commission
EU Cosmetic Ingredient Database (CosIng)
2-Amino-5-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
2-Amino-6-Chloro-4-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
2-Methyl-5-Hydroxyethylaminophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
3-Nitro-p-Hydroxyethylaminophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
4-Amino-3-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
4-Hydroxypropylamino-3-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
p-Hydroxyanisole
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Sodium Benzotriazolyl Butylphenol Sulfonate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Zinc Phenolsulfonate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
2-Amno-6-Chloro-4-Nitrophenol.
Fiume MM
International journal of toxicology, 2017
Novel Bioactive Multifunctional Polyphenols: A Chemo-Enzymatic Approach.
Flourat AL, Thiébault E, Martinez A, Brunissen F, Dosso A et al.
Chemistry (Weinheim an der Bergstrasse, Germany), 2026
2-Amino-1,2-bis(4-methoxyphenol) ethanol and its salts
Health Canada
Health Canada Cosmetic Ingredient Hotlist
2-Amino-4-nitrophenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
2-Amino-5-nitrophenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
4-Amino-2-nitrophenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
4-Benzyloxyphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
4-Ethoxyphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
4-tert-Butylphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
4,4'-Isopropylidenediphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Dinitrophenol isomers
Health Canada
Health Canada Cosmetic Ingredient Hotlist
p-Hydroxyanisole
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Phenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Phenolphthalein
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Occupational allergic contact dermatitis caused by epoxy diacrylate in ultraviolet-light-cured paint, and bisphenol A in dental composite resin.
Jolanki R, Kanerva L, Estlander T
Contact dermatitis, 1995
Effects of antioxidant polyphenols on TNF-alpha-related diseases.
Kawaguchi K, Matsumoto T, Kumazawa Y
Current topics in medicinal chemistry, 2011
Effects of antioxidant polyphenols on TNF-alpha-related diseases.
Kawaguchi K, Matsumoto T, Kumazawa Y
Current topics in medicinal chemistry, 2011
Effects of antioxidant polyphenols on TNF-alpha-related diseases.
Kawaguchi K, Matsumoto T, Kumazawa Y
Current topics in medicinal chemistry, 2011
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
Analytical Method Development and Dermal Absorption of 4-Amino-3-Nitrophenol (4A3NP), a Hair Dye Ingredient under the Oxidative or Non-Oxidative Condi
Kim HY, Kim YJ, Lee JD, Kim HR, Seo DW
Toxics, 2024
Molecular modeling and phenoloxidase inhibitory activity of arbutin and arbutin undecylenic acid ester.
Masyita A, Salim E, Asri RM, Nainu F, Hori A et al.
Biochemical and biophysical research communications, 2021
Sargassum horneri extract containing polyphenol alleviates DNCB-induced atopic dermatitis in NC/Nga mice through restoring skin barrier function.
Mihindukulasooriya SP, Dinh DTT, Herath KHINM, Kim HJ, Han EJ et al.
Histology and histopathology, 2022
Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology.
Myat Win S, Saelee M, Myo H, Khat-Udomkiri N
Journal of visualized experiments : JoVE, 2024
Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology.
Myat Win S, Saelee M, Myo H, Khat-Udomkiri N
Journal of visualized experiments : JoVE, 2024
Allergic contact dermatitis due to nonylphenol ethoxylate (nonoxynol-6).
Nethercott JR, Lawrence MJ
Contact dermatitis, 1984
Lingonberry (Vaccinium vitis-idaea L.) Fruit Phenolic Bio...
Pirjo Pärnänen, Sari Niikko, Hanna Lähteenmäki, Ismo T Räisänen, Taina Tervahartiala, Timo Sorsa + 1 more
Microorganisms, 2024
Phenolic Composition and Biological Properties of Wild and Commercial Dog Rose Fruits and Leaves.
Polumackanycz M, Kaszuba M, Konopacka A, Marzec-Wróblewska U, Wesolowski M et al.
Molecules (Basel, Switzerland), 2020
Antioxidant capacity, phenolic content, and profiling of phenolic compounds in the seeds, skin, and pulp of Vitis rotundifolia (Muscadine Grapes) As d
Sandhu AK, Gu L
Journal of agricultural and food chemistry, 2010
Phenolic-enriched maple syrup extract protects human keratinocytes against hydrogen peroxide and methylglyoxal induced cytotoxicity.
Sheng J, Liu C, Petrovas S, Wan Y, Chen HD et al.
Dermatologic therapy, 2020
Allergy to 3-nitro-p-hydroxyethylaminophenol and 4-amino-3-nitrophenol in a hair dye.
Søsted H, Menné T
Contact dermatitis, 2005
Protective Role of Phenolic Compounds from Whole Cardamom (Elettaria cardamomum (L.) Maton) against LPS-Induced Inflammation in Colon and Macrophage C
Sreedharan S, Nair V, Cisneros-Zevallos L
Nutrients, 2023
Antioxidant screening and phenolic content of ethanol extracts of selected Baja California Peninsula macroalgae.
Tenorio-Rodriguez PA, Murillo-Álvarez JI, Campa-Cordova ÁI, Angulo C
Journal of food science and technology, 2017
Zinc Phenolsulfonate.
Tucker R, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2024
Severe contact urticarial syndrome due to oxidative hair dye containing para-aminophenol and sodium-methyl-oleoyl-taurate.
Uehara S, Inomata N, Suzuki A, Matsuura M, Aihara M
The Journal of dermatology, 2014
Extraction of Polyphenols and Vitamins Using Biodegradable ATPS Based on Ethyl Lactate.
Velho P, Marques L, Macedo EA
Molecules (Basel, Switzerland), 2022
Profiling and quantification of phenolic compounds in Camellia seed oils: Natural tea polyphenols in vegetable oil.
Wang X, Zeng Q, Del Mar Contreras M, Wang L
Food research international (Ottawa, Ont.), 2017
Profiling and quantification of phenolic compounds in Camellia seed oils: Natural tea polyphenols in vegetable oil.
Wang X, Zeng Q, Del Mar Contreras M, Wang L
Food research international (Ottawa, Ont.), 2017
Formulation of Propolis Phenolic Acids Containing Microemulsions and Their Biopharmaceutical Characterization.
Žilius M, Ramanauskienė K, Juškaitė V, Briedis V
Evidence-based complementary and alternative medicine : eCAM, 2016
Verified Feb 2026
Data: PubChem · CosIng · EWG · CIR