Ingredient caution: lactic acid/AHA might cause stinging, dryness, peeling, redness and increased sun sensitivity; niacinamide is usually gentle but might cause tingling or flushing in very reactive skin; fragrance, essential oils or fragrance allergens might trigger redness, itching or allergic irritation; rich oils, butters or occlusive emollients might feel heavy or clog pores in acne-prone/oily skin. Do a patch test before applying. First-time users should start 3–4 times a week, avoid using it with retinol or other exfoliating acids in the same routine, and apply sunscreen daily. Start slowly if your skin is sensitive and avoid combining too many new actives at once. Avoid this product if you have fragrance allergy, eczema-prone skin or a damaged barrier. Use a small amount first and avoid applying on active acne if it feels greasy. Stop use if irritation persists.