What the most talked-about skincare ingredients do, in plain English.
By Shreya S · Last reviewed 15 November 2026
What is the most important skincare product?
Dermatologists almost all say sunscreen. UVB rays cause burning; UVA rays reach deeper and drive most visible ageing and pigmentation. Look for “broad spectrum” protection, SPF 30 or higher, and reapply when you are outdoors. Every other ingredient works better on skin that is protected from the sun.
What do retinol and vitamin C do?
Retinoids, a family of vitamin A ingredients including retinol, speed up skin cell turnover and are among the best-studied ingredients for fine lines and texture. They can irritate, so start slowly at night. Vitamin C is an antioxidant that brightens and helps defend against environmental damage; it is usually worn in the morning under sunscreen. Niacinamide (vitamin B3) calms redness and helps with oil and pores.
What about hyaluronic acid and ceramides?
Hyaluronic acid is a humectant: it draws water into the skin and makes it look plumper. Ceramides are fats that form part of the skin barrier, helping it hold onto that water. They are gentle and work well alongside stronger active ingredients.
What are AHAs and BHAs?
Chemical exfoliants. AHAs such as glycolic and lactic acid dissolve dead cells on the surface for smoother, brighter skin; BHA (salicylic acid) is oil-soluble and works inside pores, which is why it is used for breakouts. Do not layer too many actives at once, patch test new products, and ask a dermatologist before using retinoids if you are pregnant or have a skin condition. As we have argued, ten-step routines are rarely necessary.
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