Oral Sunscreen Pills and Polypodium Leucotomos (Heliocare): Do They Work?

There is no pill that works like sunscreen. Sunscreen sits on the skin and absorbs or reflects UV before it reaches skin cells. Supplements marketed as oral sunscreen instead contain antioxidants that are meant to reduce some of the damage after UV has already reached the skin.

The most studied ingredient is an extract of Polypodium leucotomos, a fern native to Central and South America. It is the main ingredient in Heliocare and similar products. Other "sun support" supplements combine carotenoids, vitamins C and E, or other plant extracts, usually with less evidence.

Most of the research is small. In a study published in the Journal of the American Academy of Dermatology in 2004 (Middelkamp-Hup and colleagues), healthy volunteers who took Polypodium leucotomos extract before UV exposure developed less redness and fewer signs of UV damage in skin samples than when they had not taken it. A 2017 study in the same journal (Kohli and colleagues) in 22 volunteers found that more people had a higher sunburn threshold (minimal erythema dose) after taking the extract than after placebo.

Small studies in people with polymorphic light eruption, a common sun allergy, have also reported fewer or milder reactions. Most of these trials involved dozens of people, not thousands, and several were funded by manufacturers.

The measured effect is a modest increase in how much UV it takes to turn skin red. That is a long way from the protection of a properly applied SPF 30 or 50 sunscreen, and it is not a number you can rely on at the beach.

No trial has shown that Polypodium leucotomos lowers the number of skin cancers in people. The studies measured sunburn and laboratory markers of UV damage, which are early signals, not cancer outcomes. If you take it, it can at most be an add-on to sunscreen, shade and clothing.

In May 2018 the US Food and Drug Administration sent warning letters to four companies selling dietary supplements with claims of sun protection, such as preventing sunburn, reducing sun-related skin aging or protecting against skin cancer. In a public statement, then-Commissioner Scott Gottlieb said there is "no pill or capsule that can replace your sunscreen."

Under US law, a supplement cannot claim to prevent or treat a disease such as sunburn or skin cancer. A product that promises "SPF in a pill" or cancer protection is making a claim the FDA has not accepted, which is a useful red flag when you compare labels.

In the published studies, Polypodium leucotomos extract was generally well tolerated. The side effects most often reported are mild, such as stomach upset or itching. Long-term safety data are limited, and it has not been well studied in pregnancy, breastfeeding or children.

Talk to your doctor before taking it if you are pregnant or breastfeeding, have had skin cancer, have had an organ transplant or take immunosuppressants, take medicines that make your skin sensitive to light, or have liver or kidney disease. Your doctor can check it against your other medicines.

If you and your doctor decide it is reasonable, treat it as an extra layer, not as protection on its own. Keep applying broad-spectrum sunscreen, reapplying after swimming or sweating, and keep using shade and clothing at midday. Choose a product that states the amount of extract per capsule and avoid any that promise sunscreen-level protection or cancer prevention.

The protection with the strongest evidence is still the simplest: SPF 30+ broad-spectrum sunscreen applied generously, shade between late morning and mid-afternoon, a wide-brimmed hat, sunglasses and covering clothing.

If years of sun have left you with spots you are unsure about, look at them rather than at a supplement label. A spot that is new, changing, bleeding or not healing after a few weeks should be seen by a doctor.