This is such a great question, but to be perfectly honest, for me to REALLY give it the best answer, I would need to point you to some very amazing studies done on oral sun protection products. To give you the very short version, there are many products on the market, but only a few of them come with the necessary proven clinical data. Like there are some GOOD topical SPF’s and some NOT so good ones… they are all SPF’s? The same goes for oral products. There are some VERY good products and then some that are not so good. I personally have only had any experience with two oral SPF products. Again, I also only use these myself because there is clinical proof and research papers that explain in detail what these products do and how they protect the skin. The first is the Heliocare Capsules containing Fernblock. The second is OvelleD3 by Lamelle. Why do these products work in protecting us from the sun? 1) They are brilliant anti-oxidants, 2) They reduce inflammation, 3) They boost the skin’s “immunity”, 4) They prevent DNA damage caused by the sun 5) They prevent the skin from over expressing the various enzymes that start to break down healthy skin because of sun damage.
You also have to realise, that as with regular SPF’s that you would apply topically, re-application or making sure you are using the right amount of protection for the amount of exposure is vital. So best solution is actually to use an oral SPF in conjunction with a topical one. Protection and prevention from as many different angles as possible is ALWAYS best.