Chordaria cladosiphon

BotanicalSeaweedBest with a meal

What is it

Chordaria cladosiphon is a brown seaweed species, related to mozuku (Cladosiphon okamuranus). Brown seaweeds are sources of fucoidan, a sulfated polysaccharide explored in dietary supplements for immune and digestive support.

How it works

The main bioactive in this seaweed family is fucoidan, a sulfated polysaccharide that has been studied in cell-culture and animal models for anti-inflammatory, anti-coagulant, and immune-modulating effects. Some small human trials of fucoidan from related species have explored skin, immune, and digestive endpoints. Fucoidan absorption from oral supplements is limited, but a portion may interact with gut-associated lymphoid tissue or undergo limited systemic absorption. Effect sizes in trials are typically modest.

Dosage

There is no established daily intake recommendation. Fucoidan-rich seaweed supplement doses range from 300 mg to 3 g per day across studies.

When and how to take it

Seaweed-derived supplements are typically taken with meals. Time of day is not critical.

1 commercial form

Compare the main delivery options and what they’re best suited for.

Brown seaweed extract (fucoidan-rich)

Hot-water or alcoholic extract of brown seaweed, sometimes standardized for fucoidan content.

Limited oral bioavailability; some local gut effects likely.

Safety

Generally well tolerated in published human studies. Reported side effects include mild gastrointestinal symptoms. Iodine content in brown seaweeds can be significant and affect thyroid function with prolonged high intake.

Who should be cautious

Avoid in iodine-sensitive thyroid disease, pregnancy and breastfeeding (without medical advice), and seaweed allergy. Use cautiously with anticoagulants.

Interactions

Theoretical mild anticoagulant effect from fucoidan may compound with warfarin, aspirin, or other anticoagulants. Iodine content may interact with thyroid medications.

Food sources

Mozuku seaweed (cooked)

Amount
1/2 cup
%DV
—

Frequently asked questions

What is fucoidan?⌄

It is a sulfated polysaccharide from brown seaweeds. It has been studied for immune, anti-inflammatory, and anticoagulant effects, mostly in cells and animals.

Is seaweed safe to take long term?⌄

Most edible seaweeds are safe in food amounts. Concentrated supplements raise concerns about iodine intake and potential thyroid effects.

References

Chordaria cladosiphon on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Chordaria cladosiphon (PubMed search) — PubMed link

Track Chordaria cladosiphon 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.