Hydroquinone Topical
The "gold standard of whitening" powerfully suppressing melanin synthesis
이 치료에 대해
Hydroquinone is the gold standard whitening topical agent inhibiting tyrosinase to suppress melanin production. Standard concentration is 2-4%. Not insurance-covered in Japan (self-pay/compounded or OTC). One of the most potent whitening ingredients directly inhibiting the rate-limiting enzyme tyrosinase. Efficacy for melasma, solar lentigines, and PIH proven in multiple RCTs. Famous in combination with tretinoin (Kligman formula).
작용 기전
Hydroquinone: ①binds copper active center of tyrosinase blocking tyrosine→DOPA→dopaquinone, ②inhibits melanosome formation within melanocytes, ③selective melanocyte cytotoxicity (high concentration), ④promotes melanin degradation. Multi-step inhibition suppresses new melanin while existing melanin is excreted. Reversible action dependent on tyrosinase activity.
적응증
기대 효과
Visible improvement at 5-7 weeks. 12-week trial: hydroquinone 4% achieved 76.9% pigmentation improvement. Triple combination (Kligman formula: tretinoin 0.05% + hydroquinone 4% + steroid) provides fastest and most significant effect. Effect wanes months after discontinuation; maintenance therapy important.
임상 근거
위험 및 부작용
Irritant contact dermatitis (erythema, dryness, pruritus) relatively common. Exogenous ochronosis risk with prolonged high-concentration use (>6% for years) - irreversible blue-gray pigmentation. Sun protection mandatory during use. Limited pregnancy safety data (avoidance recommended). Drug holiday recommended after 3-6 months (max continuous use ~5 months).