Key takeaways
- UVB burns, UVA ages, and visible light darkens; visible light is the one that matters most for melasma and dark marks in brown and Black skin.
- Melanin gives roughly the protection of a low-SPF sunscreen at most, and skin cancer in people of colour is found later and is more often fatal.
- Choose broad-spectrum SPF 30 or higher, use about a shot glass for the body and two finger-lengths for the face, and reapply every two hours outdoors.
- Tinted sunscreens with iron oxides avoid the white cast and block visible light; natural oils are not sunscreen.
- Check your skin monthly, including palms, soles and nails, and see a professional about any spot that changes, bleeds or will not heal.
Sun protection is the one habit that helps with almost everything else on this site: dark marks, uneven tone, early wrinkles and, most importantly, skin cancer. It is also the habit most wrapped in myths, especially the idea that brown and Black skin can skip it. This guide explains what light does to skin, how to choose a sunscreen you will actually wear, and when a spot needs a professional eye.
What sunlight actually does to your skin
Sunlight reaches you as a mix of wavelengths, and three matter for skin care:
- UVB is the shorter, higher-energy band. It is the main cause of sunburn and drives much of the DNA damage behind skin cancer1.
- UVA passes through glass and light cloud and reaches deeper. It is the main driver of premature ageing: wrinkles, sagging and the brown "age spots" that are really sun spots. Both UVA and UVB contribute to skin cancer1.
- Visible light was ignored for years because it does not burn. In a study of 20 volunteers with brown and Black skin, visible light produced pigmentation that was darker and longer-lasting than that caused by long-wave UVA, while very fair-skinned volunteers did not darken at all5. That is why it matters so much for melasma and post-inflammatory hyperpigmentation (the dark marks left after spots and rashes) in deeper skin tones4.
The myth that dark skin does not need sunscreen
Melanin is real protection, but modest. The outer layer of Black skin has been estimated to provide the equivalent of about SPF 13, nearly four times that of white skin4. That is well below the SPF 30 dermatologists recommend, and it does nothing against visible light.
Skin cancer is less common in people of colour, but when it happens it is found later and is more often fatal: 52 percent of non-Hispanic Black patients receive their first melanoma diagnosis at an advanced stage, against 16 percent of non-Hispanic white patients, and five-year survival is about 70 percent versus 94 percent3. The most common melanoma in people of colour, acral lentiginous melanoma, grows on the palms, the soles and under the nails, places that get little sun and that few people think to check3. Daily protection and a monthly skin check that includes hands, feet and nails are both part of caring for melanin-rich skin.
Choosing a sunscreen you will actually wear
Evidence: strong. Daily broad-spectrum sunscreen is one of the best-studied habits in dermatology and is considered essential for keeping melasma and post-inflammatory marks from deepening1, 4.
Mineral or chemical filters
Mineral (physical) sunscreens use zinc oxide and titanium dioxide, which sit on the skin and mostly reflect light; chemical filters such as avobenzone absorb UV instead, and hybrids combine both. Any of them protects you if the product is broad-spectrum, water-resistant and SPF 30 or higher. Dermatologists steer people with sensitive, easily stung or rosacea-prone skin towards mineral-only formulas because they irritate less1, 2.
What the label means
- Broad spectrum means UVA protection as well as UVB. If the label does not say it, assume it is not1.
- SPF measures UVB only. SPF 30 filters about 97 percent of UVB, SPF 50 slightly more, and nothing filters all of it. A higher number does not buy more hours in the sun1.
- Water resistant is for a stated time only; no sunscreen is waterproof1.
How much, and how often
Most people apply far less than the SPF test assumes. The AAD's rule is about one ounce, roughly a shot glass, for an adult body and at least a teaspoon for the face; the NHS puts the body dose at six to eight teaspoons1, 8. A handy face measure is a line of sunscreen along the length of your index and middle fingers. Apply 15 minutes before going out, then reapply every two hours and after swimming, sweating or towelling off1, 8.
Avoiding the white cast
Evidence: moderate. One controlled study found iron-oxide tinted formulas protected type IV skin against visible-light darkening better than untinted mineral SPF 50+.
Zinc and titanium are white pigments, and a thick layer looks grey or ashy on deeper skin. Tinted sunscreens solve this with iron oxides, the pigments used in foundation, which blend with your skin and absorb visible light. In a study comparing two iron-oxide products with an untinted mineral SPF 50+, the tinted products protected volunteers with type IV skin against visible-light darkening significantly better than the untinted sunscreen6. Dermatologists now recommend tinted broad-spectrum sunscreen for anyone prone to dark spots1, 2, 4. Sheer zinc formulas and chemical or hybrid filters are the cast-free alternatives.
If you have acne-prone or eczema-prone skin
For acne-prone or oily skin, look for "non-comedogenic" or "won't clog pores" on the label2; light gels and fluids usually feel best. For easily stung, sensitive or rosacea-prone skin, the AAD suggests a fragrance-free product whose only active ingredients are zinc oxide and titanium dioxide2, and that advice suits eczema-prone skin too. Patch test any new sunscreen on the inside of your arm twice a day for seven to ten days first13.
| Option | Protects against | Evidence | Best for | Watch out for |
|---|---|---|---|---|
| Mineral sunscreen (zinc oxide, titanium dioxide) | UVA and UVB | Strong | Sensitive, eczema-prone, rosacea-prone skin | White cast unless tinted or sheer |
| Tinted sunscreen with iron oxides | UVA, UVB and visible light | Moderate | Melasma, dark marks, melanin-rich skin | Still needs the SPF 30 broad-spectrum basics |
| Hats, UPF clothing, shade | Everything, while covered | Strong | Everyone | Wet or loose-weave fabric lets more through |
| Plant oils (coconut, raspberry seed, carrot seed) | Almost nothing | Lab-only, negative | Moisturising only | Never a sunscreen |
Beyond sunscreen: what works and what does not
Shade, clothing, hats and timing
Evidence: strong. Covering up and avoiding peak sun underpin every public-health sun safety programme.
The NHS advises seeking shade when the sun is strongest, which in the UK means 11am to 3pm from March to October, and treating a UV index of 3 or more as the point where protection matters8. A wide-brimmed hat shades the face, ears and neck, and a close-weave long-sleeved top protects more reliably than a cream that wears off8. UPF-rated fabric is tested for how much UV passes through; UPF 50 lets through about a fiftieth. Dark colours and dense weaves protect better than pale, loose or wet fabric.
Natural oils are not sunscreen
Evidence: lab-only, and it points the wrong way. Plant oils absorbed at least a hundred times less UV than approved sunscreen filters when tested.
You will see claims that coconut oil gives "SPF 7", raspberry seed oil "SPF 28 to 50", or that carrot seed oil replaces sunscreen. These numbers come from misread laboratory figures, not from the standardised test that produces an SPF. When researchers measured olive, coconut and other oils against approved UV filters, the oils absorbed at least two orders of magnitude less UV, and the authors concluded the protection was insufficient7. Oils such as jojoba or coconut oil are fine as moisturisers; they are not protection. Homemade sunscreen recipes are covered in DIY remedies to avoid.
A simple daily sun routine
- Morning: cleanse and moisturise as usual, and let the moisturiser settle for a minute.
- Apply sunscreen as the last step: broad-spectrum, SPF 30 or higher, tinted if you are prone to dark marks. Two finger-lengths for the face, plus ears, neck and hands1.
- Check the UV index on a weather app. At 3 or above, plan for shade, a hat and sleeves outdoors8.
- Reapply every two hours outdoors and after swimming or sweating1.
- Once a month, check your skin in good light, including palms, soles, between the toes and under the nails3.
A word on vitamin D
Your skin makes vitamin D from UVB, and sun protection reduces that. Dermatologists advise getting vitamin D from food and fortified foods rather than from deliberate unprotected sun1, and the NHS recommends that everyone consider a daily 10 microgram supplement in autumn and winter11. People with darker skin need longer in the sun to make the same amount8, and the NHS advises them to consider a daily supplement all year round11, which is a far better plan than skipping protection.
Sunburn first aid, and what not to do
On brown and Black skin, sunburn may show as tightness, tenderness or a dull darker patch rather than obvious redness, so notice how the skin feels. If you burn, the NHS advice is simple: get out of the sun, cool the skin with a cool shower, bath or damp towel, apply an unperfumed moisturiser or aftersun, drink plenty of water, and keep the area covered until it has healed9; ask a pharmacist about pain relief if you need it. Fragrance-free aloe vera gel can soothe.
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How long it takes and how to tell it is working
Sun protection works by preventing, so it is slow to show. The first change most people notice is that dark marks and melasma stop deepening in summer and begin to fade, typically over three to six months of daily use alongside a gentle routine; monthly photos in the same light are the easiest way to see it. If dark patches keep spreading despite three months of careful protection, that deserves a professional opinion rather than a stronger home remedy; see dark spots and hyperpigmentation.
When to get professional help
The ABCDE checklist covers Asymmetry, an irregular Border, more than one Colour, a Diameter above about 6 mm (a pencil eraser) and Evolving, meaning any change in size, shape, colour or feel. Two further signs matter just as much: the odd one out, a spot that looks different from all your others (dermatologists call this the "ugly duckling" sign), and a sore that does not heal10.
Our page on when to see a dermatologist explains what a skin check involves and how to find affordable care. Whatever else you change, check your skin once a month; a note in your own calendar makes it easy to remember. Our free weekly skin care tips cover sun protection alongside other everyday skin questions.
Common questions
Do people with dark skin really need sunscreen?
Yes. Melanin provides some protection, estimated at roughly SPF 13 at most, but that is well below the SPF 30 dermatologists recommend and it does nothing against the visible light that darkens melasma and post-inflammatory marks. Skin cancer is rarer in darker skin but is diagnosed later and is more often fatal, so protection and regular skin checks both matter.
How do I avoid a white cast from sunscreen?
Choose a tinted sunscreen with iron oxides, a sheer or micronised zinc formula, or a modern chemical or hybrid filter. Tinted products have the added benefit of blocking visible light, which untinted mineral sunscreens do not do well.
Is coconut oil or raspberry seed oil a natural sunscreen?
No. When plant oils were measured against approved UV filters they absorbed at least a hundred times less UV, and the researchers concluded the protection was insufficient. Oils are fine as moisturisers but should never replace sunscreen.
What should I put on sunburn?
Cool the skin with a cool shower or damp towel, apply an unperfumed moisturiser or aloe vera gel, drink plenty of water and keep the area covered. Do not use butter, toothpaste, petroleum jelly or ice, and do not pop blisters. Get medical advice for widespread blistering, fever, dizziness or any sunburn in a young child.
Sources
- American Academy of Dermatology — Sunscreen FAQs www.aad.org/sun-protection/sunscreen-faqs
- American Academy of Dermatology — How do I know if I'm using the right sunscreen? www.aad.org/public/everyday-care/sun-protection/shade-clothing-sunscreen/choosing-right-sunscreen
- Skin Cancer Foundation — Skin cancer in people of color www.skincancer.org/skin-cancer-information/skin-cancer-skin-of-color
- Tsai J, Chien AL (2022). Photoprotection for skin of color. American Journal of Clinical Dermatology. pmc.ncbi.nlm.nih.gov/articles/PMC8766623
- Mahmoud BH et al. (2010). Impact of long-wavelength UVA and visible light on melanocompetent skin. Journal of Investigative Dermatology. pubmed.ncbi.nlm.nih.gov/20410914
- Dumbuya H et al. (2020). Impact of iron-oxide containing formulations against visible light-induced skin pigmentation in skin of color individuals. Journal of Drugs in Dermatology. pubmed.ncbi.nlm.nih.gov/32726103
- Gause S, Chauhan A (2016). UV-blocking potential of oils and juices. International Journal of Cosmetic Science. pubmed.ncbi.nlm.nih.gov/26610885
- NHS — Sunscreen and sun safety www.nhs.uk/live-well/seasonal-health/sunscreen-and-sun-safety
- NHS — Sunburn www.nhs.uk/conditions/sunburn
- Skin Cancer Foundation — Melanoma warning signs and images www.skincancer.org/skin-cancer-information/melanoma/melanoma-warning-signs-and-images
- NHS — Vitamin D www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d
- NHS — Non-melanoma skin cancer: symptoms www.nhs.uk/conditions/non-melanoma-skin-cancer/symptoms
- American Academy of Dermatology — How to test skin care products www.aad.org/public/everyday-care/skin-care-secrets/prevent-skin-problems/test-skin-care-products
