Effectiveness of an oral supplement containing Polypodium leucotomos in enhancing sun protection: a clinical evaluation of minimal erythema dose pre- and post-consumption

Abstract

Ultraviolet (UV) radiation contributes to skin erythema, photoaging, and an increased risk of skin cancer. Although topical sunscreens and protective clothing remain standard photoprotection measures, poor adherence often limits their efficacy. Oral supplements containing Polypodium leucotomos extract (PLE) have gained attention as convenient adjuncts that may bolster the skin’s defenses against UV-induced damage. This study aimed to evaluate the photoprotective effects of a novel oral supplement, Sol Defense Gummies containing PLE, on the minimal erythema dose (MED) and erythema intensity in individuals with Fitzpatrick skin types I–III. Twenty-seven participants were enrolled; 25 completed the study. After baseline MED assessments without supplementation on Day 1, participants consumed 240 mg of PLE bid for five days. MED was reassessed on Day 5 to determine any changes attributable to supplementation. Erythema intensity was further evaluated via colorimetry, visual grading, and standardized photography. Participant compliance and adverse events were monitored through daily diaries and staff reviews. By blinded visual grading following a five-day supplementation period, 64% of subjects showed improvement in MED. When evaluated by colorimeter 80% of subjects demonstrated some degree of enhanced photoprotection. 20% of participants demonstrated no improvement. The mean MED increased from approximately 223 J/cm² to 234 J/cm², and 44% of participants showed a quantifiable rise in MED. Short-term oral supplementation with Sol Defense Gummies containing PLE was associated with measurable improvements in photoprotection as evidenced by increases in MED and reductions in erythema. These findings support the potential of this novel PLE delivery method as a convenient adjunct to conventional photoprotection strategies.