Nine points
What actually protects skin
Broad spectrum, at least SPF 30, every morning, all year
On the face, ears, neck and the backs of the hands — the hands being the site everybody forgets and one of the commonest places sun damage shows up thirty years later. Winter and cloud both reduce exposure and neither removes it, and glass blocks some wavelengths and not others, so a long daily commute counts.
The best sunscreen is the one you will actually wear
This is the whole of the product advice and we mean it literally. Texture, finish, whether it stings your eyes, whether it leaves a cast on your skin — these determine whether it gets used daily, and a modest sunscreen applied every morning outperforms an excellent one used twice a month. Price correlates poorly with performance.
Most people apply far too little
The protection stated on a bottle is measured at a thicker application than almost anybody uses. Roughly a teaspoon for the face and neck is the usual guide, and two fingers' length squeezed onto the fingers is the practical version. Applying half as much does not give you half the protection — it gives you considerably less than half.
Reapply outdoors, and stop worrying about it indoors
Every two hours outdoors, and after swimming or heavy sweating whatever the label claims. If you are at a desk all day, the morning application is the one that matters and reapplication is not something to feel guilty about.
Mineral or chemical is mostly a question of your skin, not of safety
Mineral filters sit on the surface and are frequently better tolerated on reactive, rosacea-prone or very sensitive skin; chemical filters are lighter and less visible. On deeper skin tones the visible white cast of some mineral products is a genuine obstacle to daily use, which is a real reason to choose a tinted mineral formulation instead.
Tinted sunscreen with iron oxide, if you have melasma or pigmentation
This is the one specific technical recommendation on the page. Visible light drives melasma and post-inflammatory pigmentation, particularly on deeper skin tones, and ordinary clear sunscreens do not block it. Iron oxide in a tinted formulation does. Patients who change nothing else and change this frequently improve.
Shade, sleeves and a hat outperform any bottle
A wide-brimmed hat protects the scalp, ears and nose at once and does not wear off. Long sleeves are more reliable than remembering to reapply on a working day outdoors. Sunscreen is the measure of last resort for the skin you cannot cover, rather than the first line.
Darker skin is lower risk, not no risk
The risk of skin cancer is genuinely lower and it is not zero, and the cancers that do occur are found later, which is what worsens the outcome. There is also a second reason that matters far more day to day: sun exposure darkens existing marks and drives melasma, so for a great many patients here sunscreen is the most effective available treatment for the complaint that brought them in.
No sunbeds, and no such thing as a safe base tan
A tan is skin responding to damage. A base tan provides a very small amount of protection against further damage, which is not a trade worth making, and intermittent intense exposure is specifically the pattern associated with melanoma. If you want the look, use something that colours the skin without ultraviolet — and note that it does not protect you at all.
Why this is the page we would keep
Almost everything else on this website treats something that has already happened. This page is the only one that changes whether it happens.
The rough scaly patches on a scalp, the brown marks across a chest, the basal cell carcinoma on a nose, and a meaningful share of what people experience as their face ageing — all of it is the accumulated record of ultraviolet exposure, arriving decades after the exposure that caused it. It is the closest thing this speciality has to a preventable disease.
It is also, unusually, advice that costs almost nothing and that we have no interest in selling you. We name no product, we sell nothing here, and the two measures with the largest effect — a hat and staying out of midday sun — are free.
Questions
Sun protection — the questions we are asked most
Do I need sunscreen in winter, or indoors?
In winter, yes, at a lower priority than in summer — daily use through the year is simpler to maintain than a seasonal habit and it is the sites that get incidental exposure, the face and hands, that accumulate the damage. Indoors at a desk away from windows, it matters much less, with one exception: if you have melasma, visible light through a window is a real driver and a tinted sunscreen is worth wearing anyway.
Which sunscreen should I buy?
We will not name one, and that is deliberate rather than evasive. Buy broad spectrum, at least SPF 30, in a texture and finish you like enough to use every morning. If you have melasma or pigmentation, buy a tinted mineral one containing iron oxide. Beyond that, the differences matter far less than whether the bottle gets opened.
Does sunscreen block vitamin D?
In practice, daily sunscreen use has not been shown to cause deficiency in ordinary life, partly because nobody applies it as thoroughly as the studies do. If you are concerned about vitamin D — and there are good reasons to be, particularly with deeply pigmented skin at this latitude — the sensible answer is a blood test and a supplement rather than deliberate sun exposure.
I have had a skin cancer. Does sun protection still help now?
Yes, and this is the point at which it stops being general advice and becomes treatment. Having had one is the strongest predictor of having another, the same exposure affected all of your skin rather than one spot, and daily protection genuinely reduces what develops next. Along with a hat, sleeves and annual examinations.
Is a high SPF much better than SPF 30?
Somewhat, and less than the numbers suggest — the difference between 30 and 50 in the proportion of ultraviolet blocked is small. A higher number does buy some margin for the fact that people under-apply. What it should never buy is longer between reapplications or more time in the sun, which is how high-factor products end up associated with more damage rather than less.
A skin examination does not find every skin cancer. A skin examination does not find every skin cancer, and any practice implying otherwise is overselling the single most useful appointment in dermatology. A careful examination finds most of what is there on the day it is performed. It can miss something very early, something in a place that is genuinely hard to see, and something that had not yet appeared when you were examined — which is why what you do between appointments matters as much as the appointment. We will show you how to look at your own skin, we will tell you which marks on you specifically are worth watching, and we will give you the list of changes that should bring you back before your next routine visit rather than at it.
A named diagnosis and a written plan you leave holding
Book an appointment
Pick a physician and a time from the calendar — it shows only the hours each of them genuinely has free. A new patient appointment is thirty minutes, a full skin examination forty-five, and you leave with a named diagnosis written down. If something on your skin has changed, telephone instead and say that word: it is triaged differently.