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← ACTIVESRECORD A-04FAMILY DEPIGMENTING AGENT

Hydroquinone

Hydroquinone

ALSO — BENZENE-1,4-DIOL

The most effective topical depigmenting agent there is, the reason every compounded pigment formula exists, and a course rather than a regimen.

THE TRIALLED STRENGTH, IN THE RANGE WE HAVE SEEN4% ——— 12%
4%

The marker is the strength the trials were actually run at. The bar is the span this register has recorded, approved and compounded together. Anything below the marker is a dose nobody has tested; anything above it is an assumption about a dose–response curve nobody has drawn.

IDENTITY & RATINGSA
INCIHydroquinone
FAMILYDepigmenting agent
MOL. WEIGHT110.11 g/mol
REFERENCE CONC.4%
RANGE SEEN4 – 12%
STATUSPRESCRIPTION ONLY
ACTS ATEPIDERMIS
ONSET8 WK
STABILITYOXIDISES — REQUIRES AN ANTIOXIDANT SYSTEM AND OPAQUE PACKAGING
TRIALS ON FILE2
IRRITATION INDEX5 / 10
STRATUM CORNEUM▸ EPIDERMISDERMIS

The shaded band is the depth this molecule is understood to reach. Anything below it is out of scope, whatever the label says.

01

Mechanism

EVIDENCE GRADE A

Competitive tyrosinase inhibitor. Reduces melanin synthesis in melanocytes without reducing melanocyte number, which is why the effect reverses on stopping.

HOUSE NOTES

  • 4% is the concentration the evidence base is built on. This register has found it compounded at 6% and at 12% — the latter on body-sized surface areas, on open-ended monthly billing.
  • Exogenous ochronosis is the risk that makes it a course. The approved label names it and notes that the majority of reported cases are in Black patients.
  • The approved triple combination states in its own limitations of use that it is not for maintenance and that melasma usually recurs on stopping.
  • In the trials, the two-drug arm without hydroquinone cleared nobody at all.

MEASURED ENDPOINTS

Melasma cleared, trial 1+23%
8 WKREF-03
Melasma cleared, trial 2+9%
8 WKREF-04

SUPPORTING RECORDS

  • REF-03A

    Randomised, active-controlled against all three two-drug combinations in the identical vehicle

    N=338 · 8 WK · INVESTIGATOR-ASSESSED

  • REF-04A

    Randomised, active-controlled against all three two-drug combinations in the identical vehicle

    N=303 · 8 WK · INVESTIGATOR-ASSESSED

02

Layering

CONFLICTS & PAIRINGS
DO NOT LAYER
  • Benzoyl peroxide
  • Indefinite use
  • Peroxides and resorcinol
PAIRS WITH
  • Tretinoin
  • A low-potency corticosteroid, short-term
  • SPF 30 daily
03

Reviewed in

6 REVIEWS
EVERY FIGURE HERE RESOLVES TO A RECORD IN THE EVIDENCE REGISTER. NOT MEDICAL ADVICE.
PREVIOUS — A-03TrifaroteneNEXT — A-05Azelaic Acid
THE DRAW · NO. 01

Win a year of
prescription skincare

One reader gets a 12 months CoreAge Rx derm plan — the compounded, physician-reviewed subscription we take apart in the register. Worth $780. Leave an address and you are entered.

PRIZE
12 MONTHS OF COREAGE RX
VALUE
$780 — $64.99/MO × 12
ENTRY
ONE EMAIL ADDRESS

VALUE IS THE PUBLISHED $64.99/MONTH SUBSCRIPTION PRICE OVER TWELVE MONTHS, AS RECORDED IN R-10. NO PURCHASE NECESSARY. WE REVIEW COREAGE RX — WE DO NOT SELL IT.

DEPTH 000%
THE DRAW · ONE READER

Win a year of
prescription skincare

One reader gets a 12 months CoreAge Rx derm subscription — compounded, physician-reviewed, delivered. The plan we score in the register.

VALUE$780
TERM12 MONTHS$64.99/MO × 12

VALUE IS THE PUBLISHED $64.99/MONTH SUBSCRIPTION PRICE OVER TWELVE MONTHS, AS RECORDED IN R-10. NO PURCHASE NECESSARY. WE REVIEW COREAGE RX — WE DO NOT SELL IT.