Tretinoin — Topical retinoid (Vitamin A acid) — retinoic acid receptor agonist

The "retinization" phase (first 6-12 weeks) of erythema, peeling, and sensitivity is often misinterpreted as skin damage — it actually reflects accelerated epidermal turnover. This phase resolves as the skin adapts. Key prescribing points: (1) Apply to completely dry skin 20-30 minutes after washing (wet skin increases penetration and irritation); (2) Always use broad-spectrum SPF 30+ daily; (3) Avoid concurrent use of benzoyl peroxide (inactivation) without buffering; (4) Pregnant patients must stop — Accutane (isotretinoin) has a mandatory iPLEDGE program. Prescription-strength tretinoin is significantly more effective than over-the-counter retinol (conversion to retinoic acid is inefficient and variable with retinol).

نظرة عامة

هذه الصفحة جزء من مكتبة المركّبات المُصنَّفة بالأدلة في Hormonaly. جميع الادعاءات السريرية مرتبطة بمصادر علمية مُحكَّمة عبر خط أنابيب التحقق المزدوج للاستشهادات.

فئة المركّب

Topical retinoid (Vitamin A acid) — retinoic acid receptor agonist

آلية العمل

Binds nuclear retinoic acid receptors (RAR-α, RAR-β, RAR-γ) regulating transcription of genes involved in keratinocyte differentiation, collagen synthesis, and matrix metalloproteinase inhibition. Key mechanisms: (1) Increases epidermal turnover — reduces corneocyte cohesion, accelerates desquamation, increases stratum corneum thickness over time; (2) Stimulates procollagen I/III synthesis in dermis via TGF-β pathway; (3) Inhibits collagenase (MMP-1) — prevents UV-induced collagen degradation; (4) Increases glycosaminoglycan deposition; (5) Normalizes abnormal keratinocyte differentiation (acne mechanism); (6) Reduces tyrosinase activity and melanosome transfer (hyperpigmentation). Gold standard for photoaged skin — only topical agent with randomized controlled trial evidence for wrinkle reduction.

الوضع التنظيمي

FDA approved — Retin-A (acne), Avita (acne/keratosis), Renova/Refissa (photodamage/fine lines)

مستوى الأدلة

High — decades of RCT evidence for photodamage; FDA-approved for acne and actinic keratosis; Kligman's original 1986 NEJM paper established photoaging reversal evidence