ear Dr Ostad, I am constantly told that an SPF does not need to be more than 40, but I notice I get brown spots if less than 60. This makes me wonder what kind of protection I need for skin cancer. Do you have any tips for choosing the right products? Are all SPF’s created equal?
First, I want to congratulate you on your proactive approach. SPF measures the protection offered in sunscreen against UVB, but not UVA rays, and while there is a wide debate about the effectiveness of SPF over 40, science supports the idea that increased protection over this number is minimal.
The key is to use a sunscreen with a PABA Oxybenzone-free SPF of 40 with at least one micronized physical blocker-zinc or titanium or both- every day, even in winter (you want micronized to avoid that thick white film no one likes).
Apply enough to give adequate protection (about a shot glass full for each area) and then reapply every three hours. It’s also important to note that heat from the sun’s rays can cause pigmentation in some cases. In these circumstances, SPF only offers limited protection whether SPF 15 or 100.