Ingredient caution: 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; 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. 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. Apply on slightly damp skin and follow with moisturiser if dryness occurs. Stop use if irritation persists.