Polypodium Leucotomos Extract (PLE) is the active ingredient in PolyPro is an extract from a tropical fern found in the rainforests Central and South America. According to the American Academy of Dermatology, ‘the main understanding is that Polypodium Leucotomos acts as an antioxidant, so it protects the skin from oxidative damage caused by sun exposure’. Studies from Harvard University found that oral Polypodium Leucotomos was associated with a significant decrease in UV- related skin damage. This is supported by many other studies on healthy volunteers which have looked at its UV protection benefits.