Skincare ingredients guide: which active does what

1.Which ingredient for which concern

Match the ingredient to the concern you most want to change. Salicylic acid and retinoids help with clogged pores and breakouts. Retinol, vitamin C and azelaic acid are used for uneven tone. Hyaluronic acid hydrates. You do not need all of them, and most people only need one.

Salicylic acid

Helps unclog pores and prevent new breakouts; can be too harsh for some skin

Retinoid or retinol

Unclogs pores, helps fade dark spots and improves texture by speeding up skin cell turnover

Niacinamide

One of the better-studied cosmetic ingredients

Vitamin C

An antioxidant used on skin against sun-related ageing

Azelaic acid

Used in dermatology for several skin concerns; ask a pharmacist or doctor about strengths

Hyaluronic acid

Hydrating rather than exfoliating; useful in dry weather

2.How to start an active safely

Introduce one active at a time, and test it first. Use it a few nights a week, and build up only if your skin stays calm. If it stings, burns or peels, use it less often or stop. Irritation can leave dark spots on darker skin tones, which is the opposite of the goal.

1. 1Patch-test on a small area before using it on your face
2. 2Start with a few nights a week
3. 3Wait several weeks before judging it, and before adding anything else
4. 4Keep wearing sunscreen every morning

If you are pregnant or planning to be, ask a doctor before starting any active, especially a retinoid.

• Sensitive skin routineHow to patch-test step by step.Read the guide

3.Do you need to layer them?

Usually not. Using several actives at once is a common way to irritate skin, and irritated skin makes it harder to tell what is working. A cleanser, a moisturiser, sunscreen and one active is a complete routine. Add a second only after the first has settled, if you still need it.

• Budget skincare routineThe four things that matter, and what to skip.Read the guide

4.Get a routine for your own skin

Saundarya AI is an AI skin analysis and grooming app that reads a single selfie and returns a personalised report: face shape, skin type, detected skin concerns with the visual evidence behind them, a morning and night skincare routine, product picks at three budgets, and an 8-week improvement plan.

Generic advice is a starting point. A scan reads your main concerns, so that you can pick one active on your own face, shows the visual evidence and a confidence score, and builds a morning and night routine around it. The first full analysis is free.

This is general cosmetic guidance, not medical advice. See a dermatologist for skin that is painful, spreading, scarring or not improving after 8-12 weeks.