Compare Supplements

Prescription topical. Hydroquinone is used at 2-4% (often as the triple-combination with a retinoid and a mild corticosteroid), applied to pigmented areas usually at night, in time-limited courses (commonly with treatment breaks) under clinician supervision, always with daily sunscreen. There is no oral or systemic use. Avoid indefinite continuous use because of ochronosis risk. This library does not provide an ingestion protocol.

Evening

Hydroquinone 2-4% cream or the triple-combination (with retinoid + mild steroid), under a clinician

Topical cosmetic only. Niacinamide is typically formulated at 2-5% in leave-on serums, creams, or gels and applied to clean skin once or twice daily (AM and/or PM). It layers well under sunscreen and with most other actives. There is no oral, injectable, or systemic dose in this cosmetic context — it is not ingested here. This library does not provide an ingestion protocol.

Any time

Leave-on topical serum or cream (2-5% niacinamide)

• For topical (skin) use only — not for ingestion, not for injection
• Prolonged continuous or high-strength use (ochronosis risk) — use time-limited courses
• Known allergy/sensitivity to hydroquinone

• Peroxides (benzoyl peroxide, hydrogen peroxide)
• Other irritating actives (retinoids, acids)

• For topical (skin) use only — not for ingestion, not for injection (in this cosmetic context)
• Known allergy or sensitivity to niacinamide or formulation excipients
• Application to broken, irritated, or compromised skin until healed

• Pure ascorbic acid (vitamin C) at low pH
• Strong leave-on exfoliating actives (AHAs/BHAs, retinoids)