Purposely Misleading Marketing Lingo: Sunscreen Edition

As you may know, I’m not a huge fan of sunscreen lotion. I just don’t think it’s all that necessary. If you’ve had enough Vitamin D skin production for one day, and you’re worried about burning up, using physical barriers – like shirts, hats, umbrellas – to impede the sunlight is better than slathering your skin with powerful chemicals. Still, in the event that the only thing standing between you and a second-degree sunburn is the application of some lotion, have at it. Just be aware that, according to a recent NY Times piece, there is some seriously misleading marketing lingo circulating in regards to SPF counts.

Wait, wait, wait. You mean to tell me sunscreen companies don’t necessarily have my best interests in mind? That Coppertone, a company whose financial success is predicated upon consumers thinking those astronomical SPF numbers actually mean something substantial, might be fudging the numbers a bit? That 90+ SPF product from Banana Boat isn’t actually more than twice as powerful as their measly 45 SPF sunscreen?

Frankly, I am shocked. Shocked and appalled. That just doesn’t sound like the Neutrogena, Coppertone, and Banana Boat, I know. These are fine, upstanding stewards of public dermatological health. Why, I’ve seen their pasty, alabaster-hued patrons buying cartons of the stuff in checkout lines, so it must be working (sure, they may have frighteningly low Vitamin D levels and brittle bones like elderly hummingbirds, but the evil sun can’t touch them!). I mean, c’mon: what could possibly compel a sunblock company to misrepresent the effectiveness of their products? It’s not like they would ever exploit our natural tendency to assume that a linear progression in SPF numbers represents a commensurately linear increase in protection from the sun. Plus, the higher SPF products tend to cost a lot more than their lowly counterparts, and we all know that the pursuit of profit never conflicts with the pursuit of all that is good and right, especially when large, multinational companies are involved – so that’s not possible. So – is it really true that the sunscreen companies are padding their stats?

Sadly, yes. 100 SPF doesn’t actually offer twice the protection of 50 SPF; the former blocks 99% of UVB rays, while the latter blocks 98%. I was no math major, and I could be mistaken, but 1% doesn’t sound like twice the protection to me. Even a sunscreen with an SPF of 30 will still “protect” you from 96.7% of UVB rays (but don’t’ expect them to put that on the package anytime soon!). At the same time as you get diminishing returns with added SPF, inadequate amounts of sunscreen result in precipitous drops in protection that fly in the face of public assumptions. Take SPF 70 lotion: if you apply half the recommended amount, the resultant protection is equivalent to SPF 8.4, not SPF 35. As you get higher in the SPF scale, the returns get smaller and smaller; as you apply less lotion, the protection sharply drops off (of course, the recommended amount often amounts to a third of the bottle!). It almost seems like the rating system, as it exists now, isn’t used to indicate protection as much as it’s intended to make consumers feel “like SPF 45 is inadequate.”

While the higher SPFs technically do offer more protection, the implied advantage is clearly overblown, and customers – their heads filled with horror stories of melanoma developing overnight after a few scant hours of unprotected sun – are generally going to go for the biggest numbers. The number 100 is twice as big as the number 50, and SPF 100 sounds twice as strong as SPF 50. Simple, basic math is anything but simple and basic when it comes to SPF.

It’s well within the sunscreen company’s purview to mislead and misdirect the hapless consumer, but hopefully those same consumers will happen across articles like this one or the NY Times’ before they get suckered in.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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56 thoughts on “Purposely Misleading Marketing Lingo: Sunscreen Edition”

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  1. I could be mistaken, but isn’t the SPF supposed to tell you how much longer you can stay in the sun without getting a sunburn compared to how long you would last with no added “protection” at all?
    I never did assume it to tell me how many percent of a certain kind of rays get blocked…
    let me know if I’m wrong.
    apart from that, I’M 100% with Mark in believing that sunscreen lotions are rather unnecessary, and don’t use them personally for the reasons mentioned in the article. which was an entertaining read, btw .)

    1. Yes, Vasco. I’m simply suggesting, as does the NY Times article, that consumers, when choosing between SPF 50 and SPF 100, for example, would choose 100 assuming that it provides substantially greater protection than 50 than it actually does. Whether the consumer understands the SPF number to be a percentage of protection (SPF 45 provides 45% protection, for example – I agree, few actually think this as you suggest) or if they relate SPF and the volume of the sunscreen used in a linear fashion (half the lotion provides half the SPF power), in either case they’d be incorrect. And, if you correctly understand SPF to be related to the length of time protection is offered, as Erik notes below (didn’t mean to make your eyes roll 😉 ), you’re still not seeing spectacular amounts of added protection within a given short time period. That is, a half hour in the sun wearing 100 provides nominal added benefits to wearing 50. I’m not saying there is no logic behind SPF, just that it can be confusing to the general public and that sunblock manufacturers profit on this fact.

  2. Well, I AM a math major, but hopefully I´m not the only one who rolled my eyes at this article (a first at MDA, btw).

    To cite wikipedia (the least you would expect even an online journalist to check up with):

    “The SPF indicates the time a person with sunscreen applied can be exposed to sunlight before getting sunburn relative to the time a person without sunscreen can be exposed. This assumes constant solar intensity over the time period”

    SPF X = (1/X)% passes through, you can stay X times as long in the sun and get the same exposure as someone unprotected. Which means (1/X)% protection.

    So it is linear in time, inverse in protection.

    1. SPF is actually a logarithmic calculation (1-1/x). However sunscreens only work for 2-4 hours and must be regularly and thickly reapplied. In Australia (world’s highest skin cancer rates) the maximum SPF factor that can be claimed is SPF30.

      The most pigmented skin has about 45x as much natural sun protection as very pale skin. A pale skinned person will get as much UV exposure in 10 minutes as a dark skinned person gets in a entire day.

      A person with a typical northern European complexion only requires 5-10 minutes exposure of the face and arms each day during summer to produce the maximum possible 8000iu of vitamin D.

      A dark skinned person who lives at a high latitude (eg Canada) will be unable to get sufficient vitamin D from sunlight even in summer.

      Vitamin D is only stored in the body for three months.

  3. I will admit to slathering up my arms and shoulders in sunscreen every day. However, I live in the southern US and bike five miles a day to work under the midday sun. As I am rather fair-skinned, without sunscreen I would be burnt. I still get a tan, so I am sure that I am still letting plenty of sunshine get through.

    I definetly don’t buy the overpriced 90 SPF stuff in the shiny bottle. The SPF 30 Coppertone baby sunscreen that I have been using since I was a kid works just fine.

    1. Actually you should only need screen screen like that for a week. by then the little bit of UV that gets through has built up a tan, and you can drop down – perhaps to 15 for a week. After that your natural protection is strong enough that you won’t need anything (but feel free to drop down to SPF 4 for a couple days).

      If you don’t have to be outside all day you can get the same results cheaper by going outside for 5 minutes at noon for a week, and then increasing.

      I’m very fair skinned. When I work inside (as I do now) I can’t go outside for more than an hour on the weekends without getting burnt. However when I worked outside one summer I was able to go completely without sunscreen within a month. I still was very light colored, but I had enough protection that to handle the outdoors.

      1. Hmm, I’ll have to do a test day and go sunscreen free in a week or so.

  4. That’s confusing.

    Even if the (1-1/X)% is correct (and doing a few calculations, I see the math works), can I really stay out in the sun 100 X longer with SPF 100 as opposed to 45 X longer with SPF 45 when there is only a difference of about 1% (98% v. 99%) of UV rays being blocked?

    And if that is the case, then any UV should absolutely fry me to a crisp in like 30 seconds, right?

    And, really, what is the difference if I can stay out 22 hours or 50 hours with the two different levels of sunscreen (which is assuming I burn in 30 minutes, comparing SPF 45 and 100 if the – you can stay out X times longer – is the SPF)? Am I going to be out in the sun for 50 hours straight? Not even possible. And is that even accurate? I guess it assumes no reduction in strength over that time, but it should, right?

    Anyway, it smells bad.

    1. How much gets blocked is beside the point: What matters is how much gets through, and 2% is twice as much as 1%. That said, the neglect of UVA and the blocking of vitamin D production are a problem even if the UVB burn-resistance numbers work out when the product is freshly slathered.

  5. SPF 90 means I only have to reapply my sunscreen every 1.5 hours. I am the color of pale marble. Left unprotected, I turn a pretty shade of magenta. And, wearing long sleeves and a hat all summer long in Los Angeles sounds awful. Plus, I hate putting on sunscreen.

    I’ve played the SPF 30 game, and let me tell you, if I fail to reapply every 30 minutes, I pink out like a communist. It’s not pretty. So, that extra hour is so totally worth it to me.

  6. I don’t really agree with the math in this article. 1% remaining UV is half as much as 2% remaining, so you get twice the length of time in the sun, assuming it’s blocking all the relevant wavelengths (questionable). I understood even as a child that the number represented a multiple of the ordinary time-to-burn, so I hardly think it’s that confusing, and I think most people understand what the number is supposed to mean.
    Of course, I’ve always hated goopy, oily stuff and smearing it on myself, and it also made sense to me as a kid that sunscreen must be helping to cause skin cancer, due to the profit motive of the manufacturers — what better way to create a self-sustaining cancer panic?
    Nowadays, we know that vitamin D deficiency greatly increases your chances of developing a fatal melanoma.
    The sun does increase your chances of treatable squamous cell carcinoma, though, but I’d take that over melanoma any day, along with the many health benefits of sufficient D.

  7. Why would sunscreen companies be any more considerate to our well being than the drug companies that try to turn healthy people into patients?

    Ironically, people who use sunblock to avoid cancer may be actually increasing their risk by blocking the vitamin D producing UVB radiation and also by exposing themselves to the chemicals that most sunscreens contain.

    For anyone who’s interested, I wrote an article about why sun exposure is so important to our health.

  8. In the beach I tend to look like a dead person, and I hardly ever tan. It’s like having the skin of a ginger, only without the freckles. Or the red hair. Anyway, I probably owe my life to sunscreens, so I love them.

    Mark I completely second your thoughts on spf. I always buy 30spf, reapply it every hour or so, and I’m fine. I love the oil-free sprays that need-no-rubbin.

    If a good 30spf work for me, it works for anyone, trust me.

  9. It’s interesting to look at the epidemiology of melanoma, tracked against stronger sunscreens since the 1930s:


    That graph is from this post about melanoma and vitamin D:


    Then, just yesterday, NYT did an idiotic post about suntanning that I just had to hit good and hard.


    What’s pretty cool about that is to go to the NYT article i linked and check out the comments. Astounding how many people called out the doctor on her nonsense.

  10. The real danger of sunscreens (about which I have written previously)is the false sense of security you get when you don’t burn or don’t get pink. Wear a 45 all day and you still (historically) expose yourself to UVA rays far far longer than if you’d worn nothing, and then gone inside or covered up when you had had a safe exposure.

  11. That’s why you buy a sunscreen that protects you from both UVA and UVB rays. Poorly researched article.

    1. This article isn’t primarily concerned with the efficacy of sunblock. Had it been, UVA would have been covered.

      But your comment does actually help my point in that it calls to attention the fact that most consumers are probably unaware of the fact that some block UVA while others don’t.

      1. This does need to be repeated.

        I think the whole “go to the beach/pool to go to sleep” nonsense needs to stop. Or the semi-nudist runners who can’t bear the weight of a track uniform.

        Not wearing sunscreen doesn’t cause cancer; stripping down to your underwear and expecting a thin layer of gunk to protect you IS what causes cancer.

        I wonder what SPF value a simple T-shirt is… perhaps SPF 10000.

  12. This sounds like a novel idea, but I do have a concern with the long term effects of UV exposure without some form of protection. Cancers like melanoma develop due to prolonged exposure to sunlight and sever sunburns.
    As far as I am aware just because you have a sun tan does not mean your protected you from harmful UV rays. Am I wrong?

  13. I don’t use sunscreen ever… I agree that a person’s probably much better off just covering up when they start getting nervous about burns.

    Of course if you’re playing/working hard in hot, humid weather that could be extremely uncomfortable though—I can’t say I really blame people for using it in situations like that. I just don’t like the idea of putting something on my skin that would likely kill me if I ate it… toxins are released through the skin but unfortunately they can be absorbed by the same route :/

  14. FWIW, i know sunscreen DOES work. I put some on and then got stuck sitting in the sun for 5 hours one day last summer and the only exposed skin that burned was the part of my back that i missed with the sunscreen. I actually had sunscreen finger-marks demarcating the protected area from the lobster-red area. This was whatever generic SPF <40 stuff i dug out of storage. Applied it once and not slathered on an inch thick. I try to balance the vitamin D thing with the knowledge that both my parents have had skin cancers in their 50s and i probably spend more time outside than them. We’re rather pale people.

  15. As a ginger kid, I burn very easily and sunscreen is one of my best friends for that reason. That, and it helps all of my tattoos from fading.
    I vote for an uplifting post next week, Mark. All of this Big Pharma, Con Agra, Big Brother stuff is starting to make me paranoid and angry. It’s time to go all Walden; built a log cabin, stop all communication, and have my parents bring me covered dishes.

  16. This is the one I use: https://tinyurl.com/p7b25a

    I can’t tell for sure if it actually blocks UVA (I hope it does though). I have trouble tolerating hot weather and the thought of wearing long sleeves in summer makes me cringe; so sunscreen seems like a gift from the gods.

    My (intentional) exposure to sunlight tends to be, almost always, less than 3 hours. More, for some reason, tends to leave me exhausted. And for that, I blame my probable perpetually-pale Nordic Grokian ancestors.

  17. So….all SPF has the same UV protection, it’s just ‘stickier’ (ie. stays on your skin longer)?

    My mother used to tell me that anything over 65 SPF is BS.

    I never researched this ‘claim’ of hers (if I did that, I’d spend my life researching…wait, I already do that, nevermind)…

  18. Wait a couple months….someone will have a “sunscreen fortified with Vit D” version…since people will need it if they don’t allow their body to absorb natural light and produce their own internal Vit D.

    The fact that we think we “need” sunscreen is a ridiculous state of affairs and takes away from people using any common sense in what they do (and how long they expose themselves to the sun). If you are pale and burn easier, going to layout for 5 hours by the pool is probably not the smartest move to make.

  19. oh yeah…it’s amazing how much the body can actually protect itself as well with the right nutrition (and cellular defenses from more antioxidants and stronger cell membranes)…as I’m Irish…and used to burn alot as a kid, now I can stay out in the sun longer as my body is no longer fuel by donuts and cinnamon rolls.

    Fruit grows in tropical climates….fruit has more vitamins/antioxidants…people in tropical climates are exposed to more sunlight…ergo nature has a build in system to protect those people if they eat more fruit? Just me contemplating outloud the simplicity of it all…..

  20. I honestly don’t get the aversion to sunscreens.

    If we accept the following statements as valid:
    1) some people just aren’t genetically equipped to produce a significant amount of melanin
    2) exposure of some skin to sunlight is, in many cases, involuntary and/or unavoidable (commuting, field work, etc)

    Then using sunscreen is nothing but the result of exercising plain, common sense.

  21. From my days on the inside, I do remember that the true hidden caveat in this whole brouhaha is that something like %90 of all unscreens wore off after a few hours so the extended protection was meaningless for the task of calculating how long you could stay out (if that time extended beyond a couple of hours). Though I don’t know if the newer “sweatproof, rubproof” versions have reduced this problem significantly or not.

  22. All I know is I put on Coppertone sport 70 SPF and didn’t burn after 9 hours in direct sunlight. Works for me. I only applied every 3 hours.

  23. Gradually introduce your body to sunlight while eating properly, and you have your own natural ‘SPF’.

    Of course certain SPFs are going to work if you’re an albino and decide one day that you need a 6 hour tanning binge. That’s just common sense.

    As for the article, I didn’t take it as Mark denouncing all SPF, he had issue with the NYT piece and the marketing of the numbering system.

  24. Very little to say on the topic of sunscreen. I wear it, because I don’t feel like wearing long sleeves and tights on my 3-4 hour bike rides (anything shorter than an hour, I go without). But I already know how you feel about long (erm, excessive) endurance exercise, Mark.

    However, I will say that this is one of the better examples of your eviscerating social commentary. You can’t buy that kind of mocking 😉

  25. Mark, I think I need to make a point here. I feel that you’ve been a little laissez faire with your research here – not so much with your evidence, more the way you used it. Let me lay down a few givens so I don’t waste time.
    I’ll assume that Grok was an outdoors type, for the sake of all the shade lovers out there. I’ll also assume that people who go outside do so with some common sense – ie, don’t bake in the midday heat etc.
    Then I’ll add one more constant to the equation. Imagine Europeans who haven’t evolved through a period of global immigration over the last few hundred years. Result? People with very cold, celtic origins now living very close to the equator (Australia, in my case). Not just in a hot country, but one with a tiny layer of ozone in the atmosphere above it.
    So, given the above – how would someone in baking heat try to interpret your article? The answer is with extreme caution.
    In Oz sunscreen is not a personal choice. It is one of MANY steps necessary in order to reduce the chances of being knocked off by one of our biggest predators (for Grok’s sake that’s well ahead of sharks and crocs!).
    It only takes one skin cell in trauma to lead to melanoma, and the number of people dying in Australia every year is up there with motor vehicle accidents. Yes, it’s that bad. In 2005, 1600 people died of skin cancer in Australia (melanoma and non-melanoma).
    Now given that Grok is a common sense outsider, who hasn’t the advantage of thousands of years of local living the risks are far greater than any personal freedoms.
    If you ask anyone in Oz about sunscreen the issues raised by your article are moot at best. For someone like me, who lives an outdoor lifestyle suncreen does what most clothing doesn’t do – provide a base UV A+B layer that is reliable. Not perfect, by any means, but reliable. This is my point – the moment we turn away from a reliable defence we are liable to send our mortality rate through the roof.
    I hope you appreciate our situation in Oz, you are obviously someone who people look up to.
    PS-From a stats point of view though, it’s well understood down here (from the government spending millions educating us) that the SPF factor is only a guide and that 30+ ranges are improbable, even with titanium etc. On that part you have my agreement.

  26. I just wanted to chime in on the “pale people who don’t readily tan like sunscreen” side. I had to laugh at the person to claimed to have “very pale” skin who took a whole hour to burn! When the sun’s high like it is now, I can’t even stand outside and talk to friends for more than a few minutes, or I start to bake and end up looking like a particularly fine cut of salmon. Going to “boiled lobster” and on to “fine blister” is not cool, so I use sunblock.

    Permanent farmer’s tan (ok, maybe not a tan per se, it’s just pink and not so white that it blinds) from getting broiled at the pool one too many times as a kid is neither healthy nor attractive.


  27. I agree with you mark. Im happy using suncream spf50++ pa from faceshop. hee hee 😉

  28. I was reading this and I can’t remember where it was I heard or read it, but the numbers on sunblock, the SPF, is actually in regards to how long it can, under ideal conditions, work to block out sunlight. And I believe it’s in like, minutes, but the number listed isn’t the actual length of time it lasts, but half as long as it can last or something? I was pretty distressed to hear about that being I’m a red-head incapable of doing anything but burning.

  29. You are very wrong on this issue, Mark.

    Sandy said it all, but just to add.. People with very pale skin absorb much greater levels of vitamin D from less sun exposure, so even with SPF, they’re probably getting more than enough.

    I live where there is an ozone hole as well and keep in mind our ancestors are not evolved for that kind of sun exposure!

    if I don’t wear sunscreen I get basically a permanent pink hue (with peeling and messed up oil production from time to time) from the 15 minutes I spend walking to and from work. This pink hue takes months to go away, even after reducing exposure.
    I think the pink hue is indicative of a chronic inflammation that I think you would agree we should avoid.
    I agree that shade and clothing are important, but those things can be misleading as well. I’ve gotten my worst burns from being in the shade without sunscreen. And unless I start wearing a ski mask to work I would get a LOT of exposure that again would lead to an inflamed pink face year round.

  30. I was told the SPF number related to the length of time before you need to re-apply the sun screen. Divide it by 10. SPF 30 gives 3 hours protection and SPF 85 provides 8.5 hours

  31. Oh…. I forgot to add to my comment above, that this is not including sweating and swimming where sunscreen is worn off. It just refers to normal everyday activity like working around home or in an office where there is UVA exposure through glass and walking around at lunchtime.