How long do topical retinoids take to work for dark elbows and knees?

Retinoids alter how skin cells mature and shed. On elbows and knees, repeated friction, pressure, dryness, and thickened skin can make the surface respond slowly. Darkening may also have a cause that a retinoid alone does not address, so a clinician may check the surrounding skin and your history.

Apply only the prescribed amount to clean, completely dry skin and follow the schedule given by your clinician. Begin less often if advised, then increase gradually as your skin adjusts. Use a bland moisturiser to reduce dryness, avoid scrubbing and picking, and protect exposed areas from sunlight. Burning, marked peeling, or worsening darkness is a reason to pause and seek treatment advice.

Arrange a dermatology review if the darkening is spreading, becomes itchy or inflamed, develops a velvety texture, or appears in several body folds. Seek advice promptly for swelling, blistering, severe pain, or a rash after application. A review is also useful when there is no meaningful change after a consistent course, because the diagnosis or treatment plan may need reconsideration.

Ask whether the colour change is linked to friction, dryness, eczema, or another condition; how often to apply the retinoid; which moisturiser is suitable; and when progress should be assessed.