Extracts of the tropical fern Polypodium leucotomos appear to have beneficial properties for the vitiligious skin. Polypodium leucotomos (also classified as Polypodium aureum) and Polypodium decumanum (also classified as Phlebodium decumanum) are indigenous to the Honduran rainforests but also can be found throughout the South American tropics and in parts of Latin America and the Caribbean. In Brazil, the common name is 'samambaia'; in Mexico and other Spanish-speaking tropical countries, the plant is known as 'calaguala.'

Indigenous people of the rainforest have long used the plants to treat and alleviate symptoms of autoimmune disorders and inflammatory conditions, including vitiligo, psoriasis, arthritis, lupus, kidney problems and malignant tumors. Its use as a tea for blood cleansing began with the Mayans, and continues today in Honduran culture.

Several clinical studies have demonstrated a significant effect of the fern on facial vitiligo. Participants were given 250 mg tablets thrice-times daily in combination with NB-UVB, twice-weekly for six months. Patients attending >80 percent of required phototherapy sessions reported a substantial repigmentation in the head and neck area, and no significant differences were seen in the other body areas. Repigmentation was more pronounced in people with lighter skin – Fitzpatrick types II and III.

The mechanism of action of Polipodium leucotomas extract is fairly complex and can be summarized into the following main points:

• Acts as a scavenger to mop up free radicals and reactive oxygen species
• Inhibits the depletion of Langerhans cells
• Reduces the number of sunburn cells
• Protects DNA by inhibiting the formation of cyclobutane pyrimidine dimers (cancer-causing cells) induced by UVB radiation.

Polypodium leucotomos extract is marketed as a dietary supplement in many countries under different names, such as Heliocare®, Calaguala and others.

The recommended dose of i.e. of Calaguala 500 mg capsules containing 100% pure Calaguala rhizome (Polypodium leucotomos) and Samambaia rhizome and leaf (Polypodium decumanum) is 2-3 capsules twice daily. It is rapidly absorbed and provides early protection that lasts few hours against the initial signs of sunburn - skin redness, or erythema reaction. However, its photoprotective effect extends beyond just decreasing the erythema reaction. The antioxidant properties of orally administered P. leucotomas extract work at protecting the skin at a deeper cellular level which is not achieved with topically applied antioxidants.

To date, Polipodium leucotomos has demonstrated an exceptional safety profile, but it has not been clinically tested in patients less than 18 years and in pregnant or breastfeeding women.