Polypodium leucotomos.

No, and no credible practitioner has ever claimed it does. Polypodium adds a small fraction of additional protection from the inside — typically described as 'one-fifth of an SPF.' It's an adjunct, not a substitute. Skip the sunscreen and you skip the protection.

Unlikely. The clinical signal builds at 6–8 weeks. Expect to commit to a full 12-week trial before deciding whether it's working for you.

The longest published safety dataset is around 12 months at 480 mg/day. For longer use, build in a 4-week pause every 6 months and discuss with your physician — particularly if you take any anticoagulants.

Because the clinical trials are small (typically n < 50), the effect sizes are modest, and the long-term outcomes are not as robust as we'd want for a Tier A. The molecule is supported, but the data isn't yet conclusive.