Male Fern

botanical

What is it

Male fern (Dryopteris filix-mas, or Aspidium filix-mas) is a perennial fern historically used as an anthelmintic (anti-parasitic), particularly against tapeworms. Its use has largely been replaced by safer modern medications due to toxicity concerns.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Tapeworm treatment (historical)

Mixed

Historical efficacy established but replaced by safer modern anthelmintics (praziquantel, niclosamide).

How it works

Male fern rhizome contains phloroglucinol derivatives (filicin, filmaron, aspidinol) that paralyze the muscles of tapeworms, facilitating their expulsion. The compounds are also toxic to human tissues, particularly the liver and central nervous system.

Dosage

Historical use only. Pharmaceutical extracts were dosed precisely under medical supervision. We do not recommend self-medication with male fern.

When and how to take it

Not applicable - we do not recommend self-medication with male fern.

1 commercial form

Male fern rhizome extract (historical)

Highly variable potency

Not in modern therapeutic use.

Safety

Male fern is potentially highly toxic. Adverse effects include nausea, vomiting, diarrhea, optic nerve damage (sometimes permanent), liver injury, kidney damage, and CNS effects. Has caused fatalities. Use has been largely abandoned in modern medicine due to safer alternatives.

Who should be cautious

Should be avoided. Particularly dangerous in pregnancy, lactation, children, elderly, and people with liver, kidney, or eye conditions.

Interactions

Interactions with hepatotoxic and neurotoxic medications; should not be combined with alcohol or fats (which increase absorption and toxicity).

Frequently asked questions

Is male fern still used for tapeworms?⌄

No. Safer and more effective modern medications (praziquantel) have replaced male fern. We do not recommend male fern use.

Why is male fern still sold?⌄

Limited niche herbal markets continue to offer it. Its toxicity profile makes it unsuitable for general use.

References

  • Male Fern on Wikidata — Wikidata link
  • Male Fern on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link
  • Research on Male Fern (PubMed search) — PubMed link

Track Male Fern with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

Coming to App Store
Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.