Ingredient caution: retinol/retinoids might cause dryness, peeling, redness, purging and sun sensitivity; rich oils, butters or occlusive emollients might feel heavy or clog pores in acne-prone/oily skin; 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. Retinol is not advised for pregnant or breastfeeding women unless approved by a doctor. First-time users should start 3–4 times a week at night, avoid layering with exfoliating acids, and use sunscreen daily. Use a small amount first and avoid applying on active acne if it feels greasy. Do not apply on broken, freshly waxed or irritated skin. Stop use if irritation persists.