p-Hydroxyanisole
molecular structure · PubChem
AKA: 4-Methoxyphenol, Mequinol, 150-76-5, 4-Hydroxyanisole, P-Methoxyphenol, Phenol, HYDROQUINONE MONOMETHYL ETHER, MEHQ, Leucobasal
Synthetic
Antioxidant
Not Clean
Mequinol is a phenol used in various applications. It is used as an inhibitor for acrylic monomers and acrylonitirles, as a stabilizer for chlorinated hydrocarbons and ethyl cellulose, as an ultraviolet inhibitor, as a chemical intermediate in the manufacture of antioxidants, pharmaceuticals, plasticizers, and dyestuffs. It is found as an active ingredient in topical drugs used for skin depigmentation indicated for the treatment of solar lentigines.
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)
Functions
Antioxidant
Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.
Reducing
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.
EWG
8
CIR
Safe as used
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
🧂Conflict of interest.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
No
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed4 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR