Ingredient Beauty BenefitsAntioxidant · Polypodium Leucotomos Extract
Polypodium: sold as 'oral sunscreen', but its firmest trial was an add-on to phototherapy
This is swallowed. In a placebo-controlled trial in healthy adults, fewer people had sunburn episodes (2 vs 8) and more had a raised redness threshold (8 vs 1). But the abstract does not give a total number of participants, and it reports outcomes as counts of people rather than means. And this ingredient's clearest trial, by numbers and design, was not cosmetic at all — it was an add-on to phototherapy for vitiligo.
Last checked Sep 21, 2026
Start here
- What it is
An extract from the leaves of a fern that grows in Central and South America. Taken as capsules.
- What it is used for
The main ingredient in supplements sold as 'oral sunscreen'.
- How it is said to work
It is said to contain several antioxidants and to reduce the damage ultraviolet leaves behind.
There are no numbers and no citations in this box. What has been established, and how far, is below.
At a glance
- In pregnancy
- Not established
- Irritation
- Minimal
- Daytime use
- ✓ Fine
- How well established
- Early research
- Concentration studied
- Not disclosed
- Length of the studies
- 8–26 weeks
Not a measurement — reported irritation grouped into five steps. It varies between people.
“Concentration studied” and “Length of the studies” are taken straight from the research on this page. They are not a recommended dose, and the figure for each finding is written out in the text.
This is not how large the effect is but how well confirmed it is. It shows the highest grade among the findings on this page.
Polypodium leucotomos is an extract from the leaves of a fern that grows in Central and South America. It is swallowed as capsules and is commonly sold as 'oral sunscreen'.
Let us settle that phrase first. What the trial below showed is that the threshold at which skin starts to redden moved up a little. It does not mean UV is blocked, and it certainly does not mean you can apply less sunscreen. That is one of the few items on this site carrying 'strong evidence'. This is not.
And reading the literature turns up something odd. The randomised placebo-controlled trial with the clearest numbers and design is not about a cosmetic use at all. It gave the extract to people with vitiligo alongside phototherapy.
Which is to say: where this ingredient is sold and where its evidence is thickest are two different places. We write that down below.
Contents
What is established
The same ingredient at a different strength, in a different formula, is a different product. These are the conditions the studies used.
The redness threshold rose — but the abstract does not say how many people there were
A 2015 US trial. Randomised, double-blind, placebo-controlled, in healthy adults aged 18 to 65 with Fitzpatrick skin types I to IV, taking 240 mg twice daily for 60 days.
Here are the results in the form the paper reports them.
- People with one or more sunburn episodes in the previous 60 days — more in the placebo group (2 vs 8, p = 0.04)
- People whose minimal erythema dose rose by day 28 — 8 vs 1 (p = 0.01)
- People whose UV-induced erythema intensity fell — 10 vs 3 (p < 0.01)
On safety, haematology, metabolic panel and clotting times showed no change over the two months.
Now how to read it.
First, the abstract does not give the total number of participants. This site does not invent numbers it does not have, so the participant field on the badge above is empty. Figures like 8 and 10 let you guess at the scale, but we will not write down a guess.
Second, the reporting is not in means. Not 'MED rose by so many mJ/cm²' but 'this many people had a higher MED'. That form hides how much it rose. One notch up and a doubling both count as one person.
Third, it ran 60 days. And one of the endpoints is sunburn episodes as the participants remembered them.
So it sits at 'early evidence'. The design is a proper double-blind placebo-controlled trial; the way it was reported does not allow more.
- Randomised controlled trial in people · sample size not reported · 8 weeks · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint instrument measurement PMID 25741399
The trial with clear numbers was not a cosmetic one — it was an add-on to phototherapy for vitiligo
A 2021 trial in Rome. To be clear first: vitiligo is a condition diagnosed and treated in a clinic, and this site does not guide that treatment. This entry is here for another reason.
It is the randomised placebo-controlled trial with the clearest numbers and design that this ingredient has.
44 people with generalised vitiligo took part, randomised to:
- 23 — NB-UVB phototherapy plus 480 mg polypodium twice daily
- 21 — NB-UVB phototherapy plus placebo
Both arms had phototherapy twice weekly for six months.
Result: the response rate for repigmentation was 47.8% versus 22%, favouring the arm with polypodium added.
What to take from it.
First, this is an add-on trial. Both arms had phototherapy. What polypodium does by itself is not something this design can say.
Second, that is why where this ingredient is sold and where its evidence is firmest do not line up. In the market this is 'oral sunscreen'. But the trial with clear numbers, randomisation and a placebo is about supporting a treatment that deliberately applies ultraviolet.
Third, 44 people, one trial. So this entry also sits at 'early evidence'.
We write this entry because where an ingredient's evidence has actually accumulated is often not where the ingredient is being sold.
- Randomised controlled trial in people · 44 participants · 26 weeks · Compared with vehicle (same formula minus the active) · Funding not declared · Endpoint clinical events (cancers, lesion counts) PMID 33433041
How to use it
- The doses were 240 mg twice daily (2015) and 480 mg twice daily (2021).
- It does not replace sunscreen. We will write that sentence once more. The trial above showed the redness threshold moving a little, not that you can use less. Compare it with the evidence behind sunscreen.
- If you are here for pigmentation, tranexamic acid, thiamidol and azelaic acid are thicker on this site.
- Evidence for applied formulations is not on this page.
Cautions
- It is swallowed. If you take other medicines, check in a consultation.
- The 2015 trial reported no change in haematology, metabolic panel or clotting over two months. But the total number of participants is not in the abstract.
- We could not find data on use in pregnancy.
- Vitiligo is treated in a clinic. The entry above records where the evidence is; it is not a recommendation for treatment.
With a new ingredient, apply a small amount somewhere inconspicuous, such as the inner arm, for two days first. Stop if it reddens or stings.
Related skin concerns
What this article relies on
- PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16