Last verified: 17 days ago
Nori Leaf
Also known as: Pyropia yezoensis, Porphyra yezoensis, dried seaweed leaf, nori
Evidence under review. — Not yet rated
Seaweed-derived ingredient with traditional use; no clinical trial data available to confirm health claims.
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What it does
Nori leaf comes from edible red algae (genus Pyropia/Porphyra) commonly used in Japanese cuisine as dried seaweed sheets. It contains iodine, vitamins B12, A, and C, along with minerals and some...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose
What the Science Says
Nori leaf comes from edible red algae (genus Pyropia/Porphyra) commonly used in Japanese cuisine as dried seaweed sheets. It contains iodine, vitamins B12, A, and C, along with minerals and some plant-based protein. Traditional and nutritional use suggests it may support thyroid function via iodine content and provide antioxidants, but no clinical trials have been identified to confirm specific health benefits at supplement doses.
What It Doesn't Do
No clinical evidence it treats any disease or condition. Don't expect proven weight loss, detox, or immune-boosting effects — these are marketing claims without trial support. Not a substitute for a balanced diet. Won't reliably correct iodine deficiency without knowing your baseline levels.
Absorption & Bioavailability
Unknown — no pharmacokinetic or absorption studies were identified in the provided data. Iodine from seaweed is generally considered bioavailable, but specific data for nori leaf supplements is lacking.
Red Flags to Watch For
- Iodine content can vary widely between products — excess iodine can harm thyroid function, especially in people with existing thyroid conditions
- No standardized dosing exists for nori leaf supplements; products may contain inconsistent amounts of active compounds
- Heavy metal contamination (arsenic, lead, cadmium) is a known risk with seaweed-derived supplements — look for third-party tested products
- 1,000+ supplement products registered in NIH DSLD despite zero indexed clinical trials — widespread use does not equal proven efficacy
Products Containing Nori Leaf
See how Nori Leaf is used in these analyzed products:
Frequently Asked Questions
What does Nori Leaf do?
Seaweed-derived ingredient with traditional use; no clinical trial data available to confirm health claims.
What is the effective dose of Nori Leaf?
No established dose
Is Nori Leaf safe?
Iodine content can vary widely between products — excess iodine can harm thyroid function, especially in people with existing thyroid conditions
What doesn't Nori Leaf do?
No clinical evidence it treats any disease or condition.
Research Sources
- General knowledge — no clinical papers were provided or indexed for this ingredient
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25