Polypodium leucotomos: Sunscreen in a pill?

A friend told me about a "sunscreen pill" that supposedly prevents sunburn. What is it? Does it really work?

- No name / No state given

Mayo Clinic dermatologist Lawrence Gibson, M.D., and colleagues answer select questions from readers.

Answer

The "sunscreen pill" you describe likely is Polypodium leucotomos extract, which is an herbal supplement marketed under the name Heliocare. This extract — which comes from a tropical, fern-like plant — has been used for many years in other countries to prevent sunburn and associated skin damage.

In addition to anecdotal evidence, three small studies have suggested that Polypodium leucotomos extract reduces the severity of sunburn. However, these trials were too small to have detected any possible side effects — meaning that the long-term safety of these extracts is still in question.

More definitive trials are needed to test both the effectiveness and safety of Polypodium leucotomos extract. It's important to note that this supplement is meant to be used in conjunction with — and not in place of — other sun protection measures, such as wearing sunscreen or protective clothing when outside.