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Do You Really Need SPF 100 Sunscreen?

When it comes to exercising, there's strength in numbers, but that's not necessarily true about sunscreen. When comparing your bottle of SPF 50 to one that's labeled SPF 100, you might get the impression that your sunscreen is inadequate. Florida dermatologist and American Academy of Dermatology (AAD) spokesman James M. Spencer, MD, explained to Web MD "SPF is not a consumer-friendly number. It is logical for someone to think that an SPF of 30 is twice as good as an SPF of 15, and so on, but that is not how it works."

To find out if sunscreens with higher SPF offer more protection


According to WebMD, SPF refers to the ability of a sunscreen to block UVB rays, which cause sunburns, but not UVA rays, which are linked to skin damage. The number doesn't indicate how long a person can be outside in the sun before suffering from a burn. To give you an idea of what the numbers mean, an SPF 15 sunscreen blocks 94 percent of UVB rays, SPF 30 blocks 97 percent, SPF 50 blocks 98 percent, and SPF 100 blocks 99 percent. No sunscreen is a 100 percent guarantee, and some doctors argue that ditching your bottle of 30 or 50 for a higher SPF could lead to a false sense of security about staying in the sun longer without reapplying.

Dermatologists suggest that rather than becoming obsessed about the SPF number, it's more important to choose a broad spectrum sunscreen (one that protects against both UVB and UVA rays), and to focus on wearing enough. A full shot glass of the stuff should do the trick. Lube up 20 to 30 minutes before heading out and be sure to reapply every two hours.

Join The Conversation
Bob-Ebisch Bob-Ebisch 4 years
Interviewing doctors for articles on sun exposure, the message I get on how high an SPF to use: as high as possible. Using the highest SPF you can get makes sense, because nobody ever gets the full value. Just preventing sunburn is an inadequate approach. One fallacy of sunblocks is that the SPF on a sunscreen actually represents the protection one gets. If you are an extremely light-skinned, red-headed Irishman, for example, it takes about 10 minutes to burn in midday, midsummer sun. SPF 15 SUPPOSEDLY means that it multiplies the time you take to burn by 15, so that would be 150 minutes, or 2 ½ hours. Yet SPF numbers are set through exposure at a very high density of sunblock application, according to San Antonio dermatologist Dr. Mark Naylor. “Nobody ever applies it that heavy or gets that value,” he adds. “Plus, people don't apply it uniformly, so they burn in some areas. Plus, it gets sweated off, rubbed off, washed off. Even so-called water-proof sunblock is not water proof, just water resistant. So that red-headed Irishman will probably burn in an hour to an hour and a half.” Another sunblock fallacy is the idea that one actually gets protection during the time before burning, that one is protected just by preventing redness. UV is still getting through and the damage, which can cause cancer and make you look much older than you are as you age, is still happening. If you are tanning day after day, you are still getting more UV than you would with a one-day burn. After a certain amount of cumulative UV has reached your skin over the years, it's easier to get cancer from additional exposure. Once you've had one episode of tumor, its' easier to get another one. Especially for such people, a higher sunscreen is needed, 50 SPF or higher, says Dr. Naylor. As a person who loves outdoor activities, Dr. Naylor says, he uses SPF 50 sunblock, and also recommends covering up to the extent possible, wearing a hat, wearing clothing that the sun does not easily penetrate. Find out more at:
sag1977 sag1977 6 years
This funny as hell, to see people talking about how they burn wtf all of you probably know the word tan right? Well i don't , I'm a true red head and yes i do need 100 prof. if i don't put it on every 35 to 40 min i get burnt after 45 min and i was born and razed in fl. As a child, we would have to go to the specialist monthly to get sunscreen. but it is over kill to put 100prof screen on an adult if you can tan. For someone like me or any one under the age of10
susanec susanec 7 years
I do 30 or 50 typically, I'm pale and at high elevation. I definitely have sunscreen nearby to reapply any time.
ClassicalTorture ClassicalTorture 7 years
My friend was told by her dermatologist to wear at least SPF 75. I don't think that means it's necessary for everyone, but there is a reason for it.
bluesarahlou bluesarahlou 7 years
Is this a repost? Why are half the comments from 2009, yet it was posted today at 330? :? Anyway...I'm horribly allergic to Neutrogena sunscreen, and most other sunscreens as well. So I won't be trying this stuff. Regardless of what level of sunscreen you should be reapplying it often. Just because you use a high SPF doesn't mean you're safe all day.
fuzzles fuzzles 7 years
No matter what SPF you use, you can save some pretty serious bucks by purchasing the Walgreen's knock-off version of the pictured Neutrogena line. It's great stuff!
wackdoodle wackdoodle 7 years
100 minutes of coverage - sure. As someone with a moderate to severe allergy to sun exposure eeking out a few extra minutes before I have to reapply sunblock would be excellent.
PaleBeauty PaleBeauty 7 years
I am Pale and when im outside i burn badly and tan easily. the extra 1-2% is well worth it to me. I not only think my pale skin is beautiful but know that with tan skin i look strange, i look unusual. so my religious use of sunscreen including spf 100 is a nessesity for me not to be in constant pain becasue of my sensitivity to the sun but also a personal preferance.
jessy777 jessy777 8 years
I use a body lotion with SPF 15 when I am going to be in and out of the sun quickly and then SPF 45 for outdoor workouts mid-day and extended periods. I have very fair skin, red hair and freckles. I am prone to sunburns and can become dark red within 15 minutes of sun exposure without sunscreen. It doesn't help I live in Texas either. I am a fanatic when it comes to coverage.
ella1978 ella1978 8 years
I'm mostly a 15 girl, with an occasional 30 if I'm going to be out for a long time w/o reapplication. And I'm super pale, it works fine for me.
ovenmitt ovenmitt 8 years
i've had cancer. it's not fun. 99% of uv protection is more than 97% or 96.7% and it is worth it.
Modus-Vivendi Modus-Vivendi 8 years
Interesting. What I have now is SPF 45, but I guess when it's time to stock up I'll go with the 30 or 15 if it's cheaper.
soapbox soapbox 8 years
Actually, I use this for my surgery scars and on a freshly lasered tattoo. (I had just got one removed) Scars+UV rays= darker scars.
Calimie Calimie 8 years
100? What a joke. For me, 30 or so is okay and I think that, for paler people, 40 or 50 would be enough. This is only marketing: pointless.
urban-chic-101 urban-chic-101 8 years
Nothing less than SPF 45 for me. Like Renee I live in a very hot climate. You walk outside it feels like the you open the door to a hot oven, your skin just sizzles. I think main objective is that just because you're wearing a higher SPF doesn't mean you need reapply less.
doogirl doogirl 8 years
I use SPF 30 religiously, and reapply often. I don't think I'll be buying the SPF 100, it seems to me to give a false sense of protection. Reapplying often is the key!
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