According to the manufacturer:
"Life Extension offers an oral supplement to help protect against harmful solar radiation. During a decade of clinical trials, FernBlock has shown remarkable effectiveness in shielding skin against dangerous ultraviolet exposure. Studies have shown that this fern extract has a high affinity for skin tissue and helps protect against ultraviolet damage shown to cause premature skin aging and wrinkling.
FernBlock is a natural extract derived from the fern plant Polypodium leucotomos. Used as a sunburn remedy by native Indians for centuries, this natural fern extract has been formulated by international scientists affiliated with leading institutions.
The highly targeted action of FernBlock safely inhibits the absorption of harmful ultraviolet rays and quenches dangerous free radicals. FernBlock also helps mitigate the consequences of excessive ultraviolet radiation by reducing the number of skin cells that indicate sun-induced injury. Additionally, it helps inhibit pro-inflammatory cells that cause redness and itching, blocks protein-destroying skin enzymes that decrease skin elasticity, and preserves the skin’s antioxidant status.
This product has been upgraded to contain Red Orange Complex, a standardized extract that is obtained from three red orange varieties—Citrus sinensis var. Moro, Tarocco, and Sanguinello.
The main active phenolic compounds include anthocyanins, flavanones and hydroxycinnamic acids (as well as ascorbic acid), which work together to support the body’s natural photoprotection against ultraviolet radiation. They do so by helping to balance the body’s normal inflammation response, free-radical defense mechanism, and healthy apoptotic (cell death) activity
In a controlled human trial, 15 days of oral supplementation with Red Orange Complex was demonstrated to measurably support natural skin defenses against ultraviolet radiation.
FernBlock is designed to complement topical sunscreens for intense sun exposure. Topical sunscreens are effective if properly and regularly applied, especially for long periods of sun exposure. FernBlock supplements topical sunscreens by protecting the entire skin surface and has an obvious advantage since it cannot be removed by perspiring or bathing."