Read the UV index before you skip it

The two health bodies this page checked agree closely. The British health service says an adult covering the whole body needs around six to eight teaspoons, put on thirty minutes before going out and again just before; the American dermatologists say fifteen minutes before, on dry skin. Both say reapply about every two hours outdoors, and straight after swimming or heavy sweating — one account says it simply does not last all day, and two separate conversations say putting it on when you arrive leaves you unprotected while it binds, which is what the fifteen to thirty minutes is for. The places people miss are the places the accounts and the dermatologists list together: ears, the back of the neck, the tops of the feet, the backs of the hands, the top of the head, the chest, and around the eyes — one caution says that last is skipped because it stings and pays for it later, which is one caution and not checked here; how to handle the stinging around the eyes is one of these conversations’ own gaps. One exchange, one account to one, argues whether a day cream with SPF is enough, and two cautions answer: only if you put on as much of it as you would of a sunscreen, which is far more than a face cream gets, and it may not carry the UVA protection its number implies — look for the UVA rating on the tube, which in Britain is a star system and the health service asks for four stars. Check the date: one account says an expired bottle will not protect you, the regulator says a bottle with no date is expired three years after you bought it, and the health service points to the open-jar symbol with a number of months on it. Keep the bottle out of the sun — the regulator’s words — and one account says do not keep it in the cooler either, because cold separates the formula, which stands against two accounts in that exchange who like the cold feel of it. How often to reapply if you only step outside briefly during an indoor day is a gap in these conversations.

Three separate conversations say it does, two corrections say it does not, and the authorities land between them: the American dermatologists say sun protection may decrease your skin’s production of vitamin D and recommend getting it from food or a supplement instead; the British health service says strike a balance between protecting yourself and getting enough vitamin D from sunlight, that children under five should take a supplement regardless, and that people with darker skin may need more sun to make the same amount. So the accounts on both sides overstate it. What they agree on, and the authorities with them, is the practical answer: one account says if you are worried, a blood test tells you and a supplement fixes it; three accounts in one note say supplement rather than sunbathe; one account says the deficiency people actually have comes from short winter days and indoor lives, not from the cream. One account says humans evolved to need sunlight for a list of things and that hiding from it is unnatural; the three accounts who answer say the same ancestors did not live long enough to get skin cancer. Whether the balance for you is a supplement or ten minutes of morning sun on your arms is your doctor’s question, and how much vitamin D a modern sunscreen actually blocks is a gap in these conversations.

Three separate conversations say some of the filters are harmful and that sunscreen should be rinsed off rather than worn all day; this is the argument the page checked hardest. The United States medicines regulator’s page, read this year, says in its own words that at least some active ingredients are absorbed through the skin and enter the body, that this makes it important to find out whether that carries any risk, and that it has asked the industry for the data to confirm safety — and on the same page it recommends a broad-spectrum sunscreen of at least SPF 15, reapplied every two hours. That is the honest position: absorbed, safety data outstanding, use still recommended, because the harm from ultraviolet light is not in doubt. Two corrections in these conversations settle the benzene scare: it was a contaminant found in some batches, not an ingredient, the affected products were recalled, and it turned up in trace amounts in shampoo and toothpaste too. One correction puts the trade plainly — the sun causes cancer, and that is a larger risk than the theoretical one from the cream — and three accounts in one exchange say the same against two who say rinse it off. If you would rather not wear the chemical filters, the accounts and one correction give you the other kind: a mineral sunscreen, zinc or titanium, which sits on the skin rather than absorbing into it; one caution says it can leave a white cast and two say some people find it protects less well, and the comparison is one of these conversations’ own listed gaps. Which filters are safest, and which are safe in pregnancy or for a skin condition, are gaps in these conversations — a pharmacist or a doctor is the page for that.

The argument in these conversations is long and does not settle, so here is its shape with the counts. Two separate conversations say the common chemical filters harm reefs and that you should swim in a mineral sunscreen or in clothing; against them single accounts say the effect is trivial beside warming seas and plastic, and the exchanges run four accounts to two, three to two, and two to four in three separate conversations. Nobody in the argument wins; one account says Hawaii regulates which sunscreens can be sold, and the fact this page checked by search is that the state of Hawaii banned the sale of sunscreens containing two of those filters, oxybenzone and octinoxate, from the start of 2021, and by one search-found account of later legislation added two more from 2023 — the page names the state and leaves the rest of the science to the people who study coral. Three cautions say the words ‘reef-safe’ on a label are not regulated and mean whatever the maker wants; one correction says even a mineral sunscreen is only the kind reefs are thought to tolerate if it is the non-nano sort that leaves a white film, and one caution says that sort washes off easily. One account says a long-sleeved swim shirt does the job of most of the cream and puts nothing in the water; one says use up the bottle you have before buying a virtuous new one. The rest — how much of the bleaching is the cream, at what concentration, by what mechanism — is a gap in these conversations.

Three separate conversations say the texture is the reason they do not wear it — heavy, greasy, stinging when they sweat — and one account with a sensory condition says nearly every formula is unwearable for them. The accounts’ answers, with the brands they name left out: a lighter gel or fluid rather than a cream; a mineral formula if the chemical ones sting the eyes, or a chemical one if the mineral leaves a white cast; and one account says test anything new on the inside of a forearm before it goes on your face. One account says the non-greasy ones are dear, one says the price is the real obstacle, and one says that in the United States a health savings account will pay for sunscreen. One account with acne-prone skin says it breaks them out and that is an unsolved trade for them; which formulas suit acne-prone or sensitive skin is one of these conversations’ own gaps. Two accounts in one note say the extra step in the morning is why they skip it, and one account says they would rather have the wrinkles than the step — which is a decision this page leaves with you, and the UV index makes it a decision for some days rather than every day.

Because the damage is slow and the accounts who have it are specific. Two separate conversations say it prevents skin cancer, and the places they name are the chest and the back of the neck; two carry stories of nearly losing part of a body to it, or of twins who aged visibly differently. Two separate conversations say the change is visible and uneven across the skin that was exposed, and single accounts say daily use from their early twenties left them at forty-five without lines under the eyes, that starting in your thirties is still worth it, and that one dermatologist after another gives the same instruction. Two separate conversations say dark skin gets skin cancer too and that it is found later because it was not being looked for — the dermatologists’ line is that anyone can, whatever their skin tone. One correction says a hat is not enough on its own; the account who wears only a hat all day outdoors and feels fine is in these conversations too. One account says tanning beds drove the numbers up and are banned in places; four accounts in one objection prefer a tan to the protection and are answered that tanned skin ages faster. The accounts who say the whole thing is vanity are here as well, two to two in one exchange, and this page does not settle whether you care about lines; it notes that the cancer part is the health services’ claim, and two conversations’ as well.