Compare Supplements

Topical cosmetic only. Leave-on glycolic acid is used at roughly 5-15% in lotions/serums (often at low pH), applied to clean skin a few nights per week and building as tolerated; professional peels (20-70%) are applied in-office at intervals. There is no oral, injectable, or systemic dose — it is not ingested. Pair with daily sunscreen. This library does not provide an ingestion protocol.

Evening

Leave-on lotion or serum (≈5-15% glycolic acid)

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
• Known allergy or sensitivity to AHAs
• Active eczema, dermatitis, or broken/sunburned skin until healed

• Other leave-on actives (retinoids, other acids, benzoyl peroxide)

• 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)