tuneTypical Dose
Product-specific daily oral doses in controlled trials
Polysaccharide
Fucoidan
Fucoidan
Evidence TierCWADA NOT PROHIBITED
watchEffect Window
Controlled trials generally track changes over weeks to months.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Fucoidan has interesting early human data in gut-microbiome and liver-fat settings, but the evidence is product specific and still exploratory.
Fucoidan is usually sold as an immune and anti-inflammatory seaweed compound, but the most relevant human evidence is still early and preparation specific. A recent placebo-controlled trial supports real microbiome modulation in healthy adults, while the NAFLD signal comes from a fucoidan-fucoxanthin combination rather than fucoidan alone. That keeps the overall evidence exploratory rather than clinically established.
Fucoidan is a sulfated polysaccharide from brown seaweeds with proposed immune, anti-inflammatory, and microbiome-modulating effects. Human data remain early and product specific.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Experimental support for microbiome modulation
Secondary Outcomes
- Preliminary combined-product support in NAFLD
Safety
Contraindications and Interactions
Contraindications
No entries provided
Side effects
- Mild GI symptoms
Interactions
No entries provided
Avoid if
- You are extrapolating one fucoidan product's effect to all seaweed extracts
Evidence
Study-level References
fuc-SRC-001Randomized, double-blind, placebo-controlled, three-arm trial
Sourceopen_in_newGut Microbiome Modulation and Health Benefits of a Novel Fucoidan Extract from Saccharina latissima. A Double-Blind, Placebo-Controlled Trial. Microorganisms. 2025. PMID:40732054.
Population: Healthy adults in a three-arm microbiome trial.
Dose protocol: 125 mg or 500 mg twice daily for 4 weeks
Key findings: Dose-dependent microbiome diversity and taxa improvements.
Notes: Best modern human fucoidan study.
Paper content
This 4-week placebo-controlled trial found that fucoidan from Saccharina latissima improved microbial diversity in a dose-dependent way, raised Bifidobacterium, Faecalibacterium, and Lachnospiraceae abundance, and reduced inflammation-associated taxa. Functional pathway analysis also suggested greater short-chain-fatty-acid biosynthesis potential. The study supports a real microbiome effect, but it still does not establish a hard clinical benefit in disease settings.
fuc-SRC-002Randomized controlled trial
Sourceopen_in_newShih PH, et al. Fucoidan and Fucoxanthin Attenuate Hepatic Steatosis and Inflammation of NAFLD through Modulation of Leptin/Adiponectin Axis. Mar Drugs. 2021. doi:10.3390/md19030148. PMID:33809062.
Population: Adults with NAFLD.
Dose protocol: Low-molecular-weight fucoidan plus high-stability fucoxanthin for 24 weeks
Key findings: Improved steatosis and inflammatory markers in NAFLD.
Notes: Useful but combination-specific.
Paper content
This is a useful human proof-of-concept for fucoidan, though the active intervention combined fucoidan with fucoxanthin rather than testing fucoidan alone.