Tinted sunscreen

Choosing it for deep skin

• Look for SPF 30 or higher and "broad spectrum". Many "skin tints" have no SPF at all.
• Choose one tinted with iron oxides. They block visible light, which can darken dark marks and melasma on deep skin.
• Untinted mineral (zinc oxide, titanium dioxide) sunscreens can look ashy or purple on deep skin. Test on the jaw in daylight.
• In humid months a light fluid or gel feels best. In harmattan a creamier one helps dry skin.

How to apply

1. Apply it last in your skincarePut it on after moisturiser and before any makeup.
2. Use enoughFor face and neck, use about two finger-lengths. Using less gives much less protection than the label says.
3. Dot, then spread evenlyDot it over your face and spread it out. Include your ears, neck and hairline.
4. Let it setWait a few minutes before makeup so it does not streak.
5. Reapply when outdoorsReapply every 2 hours outside and after sweating. An SPF stick or powder works over makeup.

How long to wear it

• Sun, sweat and wiping wear it off. Reapply every 2 hours outdoors and straight after heavy sweating.
• Sweat shifts the tint. Blot with a tissue or blotting paper; do not pile on more layers.
• Take it off every night. Water-resistant formulas may need an oil or balm cleanser first.

Safety and the evidence

• In a randomised trial, an iron-oxide sunscreen that blocks visible light improved melasma more than a UV-only sunscreen.

  Evidence B — one RCT (both groups also used a lightening cream) · Castanedo-Cazares 2014 — visible-light sunscreen in melasma (RCT)

• Look for SPF 30 or more, broad spectrum, and reapply every 2 hours outdoors.

  Evidence A — sunscreen class; dermatology guidance · American Academy of Dermatology — how to apply sunscreen

• Some chemical filters, such as octinoxate or oxybenzone, occasionally cause allergic or light-triggered rashes.

  Evidence C — case series

• Fragrance (parfum, aroma) and botanical extracts are the commonest cosmetic allergens; choose fragrance-free if your skin reacts easily.

  Evidence B/C — patch-test series

Evidence grades: A systematic reviews or several trials; B at least one trial or consistent controlled studies; C observational studies, surveys or case reports; D expert opinion.

Keep it clean

• Keep it out of heat and sun: not in a parked car, on a sunny dressing table or in a handbag left outside. Heat spoils makeup before its date.
• Throw it away after the expiry date, or sooner if it separates, smells odd or changes colour.
• Shake it before use if the label says so; the tint settles.