It is impossible to judge the effectiveness of a product without looking at the entire product with all its ingredients rather than the percentage of only one ingredient or even the presence or absence of an ingredient. One ingredient does not make a product; rather, all the ingredients and their interaction together make the product and determine its effectiveness. For sunscreens, there is a uniform measurement of effectiveness and in the U.S. that is the SPF. In other areas of the world, other measurements may be used but, since iS Clinical sunscreens are sold throughout the world, our sunscreens have a similar measurement required by regulations in various markets. All 3 of these iS Clinical sunscreens use micro-encapsulation technology but in each the technology is slightly different. This, plus the addition of the other ingredients, will affect the formula’s performance in many ways, including SPF testing.