Hands down, this is the fact that surprises people the most when I’m boring them about sun protection.
Very few people know or use the correct sunscreen dose.
To achieve the stated sun protection factor (SPF) on any sunscreen, you must use the correct dosage.
If you think about it, it makes sense. Use less and you’re reducing the dosage. Just like pills when you have a headache. Except in this case, you’re lowering the SPF by lowering the dose.
I regularly hear people complaining that they burnt even whilst wearing sunscreen. So often, this is because they did not use enough.
So, what is the correct dose?
To keep things really simple, follow this rule of thumb :
This rule applies to ALL sun screens, no matter which brand.
If the body is made up of two legs, two arms, one face, one chest and one back, that’s seven body parts.
If you were at the beach and intending to cover your entire body, that would be seven teaspoons or 35ml (7 x 5ml).
Now, it’s easy to see why you burnt last summer when you thought you had plenty of cream on.
Suddenly, you can also see why a 200ml bottle shouldn’t last an entire summer, with some to spare for next year’s summer holiday. Really, a 200ml bottle equates to just under six full-body applications (6 uses x 7 body parts x 5ml = 210ml).
All sunscreens must be tested before they can be put into the market place. The testing that gives them their SPF scores is based on this exact dosage. So, use less and you’re diluting the potency or defence credentials of any sunscreen.
I know this implies you need to use more cream and therefore spend more. But surely, it’s a small price to pay?
Thanks so much for reading. Contact me anytime on firstname.lastname@example.org if you have any questions or requests.