I’ve previously described the consequences of acute and chronic sun exposure, and the rationale for topical sunscreen products. But wouldn’t it be easier to just take a pill that can boost our skin’s resistance to to the harmful effects of the sun? Is it possible to get all the benefits of sunscreen without the bother of creams, or even clothing?
Protecting your skin from ultraviolet (UV) damage is the central claim with products like Heliocare, Fernblock, and Sunpill. All contain extracts of Polypodium leucotomos (cabbage palm fern), a plant native to Central America. Like many plants, there are some interesting biological compounds inside. The active ingredients seem to be in the rhizome (rootstalk), and they include calagualine, ecdysone, ecdysterone, and several phenolic compounds that may provide antioxidant effects. There is some preliminary evidence to suggest that these chemicals may reduce oxidative damage caused by UV light. In animal models that have looked at simulated UV radiation, inflammation and irritation have been reduced.
During a decade of clinical trials, FernBlock® has shown remarkable effectiveness in shielding skin against dangerous ultraviolet exposure [source]
So let’s look at this evidence, and start with a focused clinical question: In typical sunscreen users, does consuming Polypodium leucotomos supplements provide UVA and UVB skin protection that is comparable to, or a substitute for, topical sunscreen products?
A search of the literature identified four semi-relevant trials. There are no published studies that directly compare oral supplements to topical sunscreens.
Villa studied the effect of Polypodium leucotomos on a marker for chronic UVA-initiated skin damage. Ten volunteers were recruited, and all underwent pre-study skin biopsies and UVA exposure to identify baseline values. One week later, five participants took two doses of a Polypodium leucotomos supplement (8 hours and 2 hours before UVA exposure), and the others received no treatment. Then all received another dose of UVA radiation, at 2-3x the minimum dose determined to produce a sunburn. More biopsies were taken to evaluate UVA damage.
The authors reported that the control group experienced large increases in the marker for UVA damage, while the Polypodium leucotomos group experienced decreases, compared to control. However, these results were not statistically significant. Further, the authors noted that Polypodium leucotomos did not prevent inflammatory infiltrates associated with UVA damage.
The limitations to this study are numerous: The sample size of 10 is modest, and no information is provided to demonstrate the groups are well matched, or how they were allocated. No rationale for the dose used is provided. Two patients were dropped from the control group. The study was not blinded for participants. There is no information about the product used, other than it was a 240mg dose. Without standardization, it’s impossible to extrapolate the observed effects to any commercially available product. Finally, given it appears to be a letter to the editor, it may not have been subject to peer review. The results should properly be called hypothesis-generating — at best. They look promising, but should be followed by more study – not routine use.
Middelkamp-Hup studied Polypodium leucotomos in the prevention of sunburn. In this small open-label study, nine volunteers were given different doses of UV radiation, and then the radiation was repeated after two days of taking Fernblock. A small skin biopsy was taken before and after treatment, and the samples were compared. Researchers found less evidence of skin damage, and concluded that Fernblock protected the skin from inflammation and the effects of sunburn. This was an interesting preliminary study, but not one that helps us understand its effectiveness compared to sunscreen. The study was not blinded, the effects were modest, and long-term effects were not studied.
Another study by the same author examined the effect of Polypodium leucotomos in ten volunteers that were given sensitizers that accelerate UV damage. There was no blinding. Volunteers received simulated sun exposure before and after 7.5mg/kg of Polypodium leucotomos. The author concluded that Polypodium leucotomos was an effective skin protector against the simulated sun exposure. As this study examined the products effectiveness in patients given UVA sensitizers, it’s difficult to draw conclusions about its usefulness in typical consumers seeking protection from regular or intermittent sun exposure.
González studied both topical and oral forms of Polypodium leucotomos in 21 people. Some patients were given sensitizers to accelerate UVA damage, some were untreated. Skin was evaluated to measure the protective impact of the product. The author observed that the time to initial reddening increased significantly, and reduced other initial signs of skin damage. He concluded that both versions offered some degree of skin protection. This was a small study, with no blinding. No comparison was made to sunscreen.
That’s the extent of the published research that’s relevant to our question. There are some other trials, that are suggestive, but not conclusive, that Polypodium leucotomos supplements may provide some benefit to people who have atypical skin reactions to sunshine. Without double-blind trials, we are left with considering this lesser-quality evidence. That doesn’t mean we ignore the published data, but we should remain skeptical, and look for confirming evidence.
Unfortunately, the manufacturer’s websites have little in the way of objective clinical information. The Sunpill manufacturer links to this clinical study summary [PDF], but there’s not enough information to evaluate the results. There is also a laboratory report [PDF] of a Sunpill evaluation designed to follow the FDA’s standard for sunscreen testing. An eight week evaluation, it measures the efficacy of the supplement in conjunction with daily sunscreen use. While the results look promising, it’s difficult to draw conclusions from the data when presented in this format.
Dosing and Use
If you read the marketing, these products sound pretty impressive:
Fernblock: For the first time you can achieve essential protection from dangerous sun exposure in a pill.
Heliocare works to turn back the sun.
Sunpill protects the skin from the harmful rays of the sun, but still allows your body to receive the benefits that sunshine gives you.
Clearly there’s a gap between the marketing copy and what the evidence says. In light of the limited clinical data, let’s look closer at the dosing recommendations. Are manufacturers telling consumers to put away their topical sunscreen? Not quite:
- Fernblock‘s dose is 240-480mg in the morning, 30 minutes before sun exposure, and “for extended sun exposure take one additional capsule at noon.” The manufacturer also recommends use with SPF 30 sunscreen, and cautions, “Use topical sunscreens whenever exposed to sunlight. This product is not a sunscreen.”
- Heliocare has a similar dose: two 240mg capsules daily before exposure to sun, with a third capsule for prolonged exposure to the sun. There is a caution: “Do not exceed the stated recommended daily consumption of three Heliocare capsules per day.” The manufacturer also notes, “Heliocare is definitely NOT a substitute for good sunscreens and protective clothing.”
- Sunpill is packaged as a 639 mg dose of Polypodium leucotomos and several other ingredients including green tea, aloe, pomegranate, and beet root, all without persuasive evidence of effectiveness for UVA/UVB sun protection. It’s not clear how much Polypodium leucotomos is in the product. The manufacturer states, “New research from the University of Miami School of Medicine shows that the fern extract in these pills significantly reduced UVA-related DNA damage that leads to wrinkling and brown spots. For best results, pop one each day starting a week before you plan on fun in the sun.” It also adds, “It is alway (sic) advisable to use a topical sunscreen when you are going to be out in the sun for an extended period of time.”
The most common side effect reported in the limited research is stomach upset. Advertisers repeatedly use the statement, “has been safely used for over 20 years in Europe,” but I can find no published evidence of this. Based on the the evidence above, these products seems to be safe when taken for a week – the longest trial that’s been published. There is no published information showing these Polypodium leucotomos products are safe if taken for a longer period.  Another formulation of the same ingredient appears to be safe when taken for up to five months, however.  In light of the small studies that have been conducted, the full safety profile may not yet be well understood. There’s no information about the supplement’s safety in children, or in pregnant or breastfeeding women.
The consequences of unprotected exposure to UV light can be severe. Physical barriers and sunscreen in the forms of creams and other topical products have been demonstrated to reduce acute and chronic consequences of UV exposure. The idea of a well-tolerated, safe, oral supplement that protects against UVA and UVB without the need for topical products is an attractive one – but it’s not clear we have the evidence yet. Oral sunscreens, taking the most optimistic view of the data, may slightly reduce some of the severity of a sunburn, and may provide some UVA protection. González, one of the researchers cited above, has suggested Polypodium leucotomos offers an SPF of about 3 – insufficient for most people that need sunscreen. Most importantly, these products are still recommended for use in combination with topical sunscreen. Given most sunscreens offer an SPF of 15 or more (when properly applied), it’s not clear if the incremental benefits would be meaningful. So do the potential benefits outweigh the unanswered questions and additional cost? Until better effectiveness and longer-term safety data emerges, a risk-benefit evaluation suggests we’re better off seeking shade behind, instead of eating, Polypodium leucotomos.
 Natural Medicines Comprehensive Database [database on the Internet]. Stockton (CA): Therapeutic Research Faculty; 1995-2010 [cited 4 July 2010] Available from: http://www.naturaldatabase.com. Subscription required to view – Sorry.
 Villa, A., Viera, M., Amini, S., Huo, R., Perez, O., Ruiz, P., Amador, A., Elgart, G., & Berman, B. (2010). Decrease of ultraviolet A light–induced “common deletion” in healthy volunteers after oral Polypodium leucotomos extract supplement in a randomized clinical trial Journal of the American Academy of Dermatology, 62 (3), 511-513 DOI: 10.1016/j.jaad.2009.05.045
 Middelkamp-Hup MA, Pathak MA, Parrado C, Goukassian D, Rius-Díaz F, Mihm MC, Fitzpatrick TB, & González S (2004). Oral Polypodium leucotomos extract decreases ultraviolet-induced damage of human skin. Journal of the American Academy of Dermatology, 51 (6), 910-8 PMID: 15583582
 Middelkamp-Hup MA, Pathak MA, Parrado C, Garcia-Caballero T, Rius-Díaz F, Fitzpatrick TB, & González S (2004). Orally administered Polypodium leucotomos extract decreases psoralen-UVA-induced phototoxicity, pigmentation, and damage of human skin. Journal of the American Academy of Dermatology, 50 (1), 41-9 PMID: 14699363
 González S, Pathak MA, Cuevas J, Villarrubia VG, & Fitzpatrick TB (1997). Topical or oral administration with an extract of Polypodium leucotomos prevents acute sunburn and psoralen-induced phototoxic reactions as well as depletion of Langerhans cells in human skin. Photodermatology, Photoimmunology & Photomedicine, 13 (1-2), 50-60 PMID: 9361129