Adapalene 0.1% is a third‑generation topical retinoid for acne, with comedolytic, anti‑comedogenic, and anti‑inflammatory actions that normalize follicular keratinization and reduce inflammatory signaling. It selectively binds RAR‑β/γ receptors to modulate gene transcription, decreasing microcomedone formation and lesion counts over time. Compared with older retinoids, adapalene is more photostable and remains compatible with benzoyl peroxide, enabling fixed‑dose combinations for enhanced efficacy. Systemic absorption from 0.1% gel/cream is minimal, and the molecule’s stability supports consistent nightly use as a foundation of guideline‑based acne regimens and maintenance therapy.