Ingredient caution: high-strength niacinamide might cause flushing, tingling or small bumps in reactive skin; fragrance, essential oils or fragrance allergens might trigger redness, itching or allergic irritation; preservatives such as phenoxyethanol/benzyl alcohol might sting very sensitive or compromised skin; humectants such as hyaluronic acid/glycerin are usually gentle but might feel sticky or tight if not sealed with moisturiser. Do a patch test before applying. First-time users should start 3–4 times a week and reduce frequency if redness or bumps appear. Avoid this product if you have fragrance allergy, eczema-prone skin or a damaged barrier. Do not apply on broken, freshly waxed or irritated skin. Apply on slightly damp skin and follow with moisturiser if dryness occurs. Stop use if irritation persists.