Safety Profile
Known Safety Concerns
- Triggers both hypothyroidism and hyperthyroidism depending on thyroid status
- Kelp supplements have unpredictable and sometimes extremely high iodine content
- Particularly dangerous in Hashimoto thyroiditis and nodular goitre
- UL: 1,100 mcg/day — frequently exceeded by kelp and seaweed supplements
Contraindications
- Triggers both hypothyroidism and hyperthyroidism depending on thyroid status
- Kelp supplements have unpredictable and sometimes extremely high iodine content
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
Iodine is essential for thyroid hormone synthesis. Supplementation carries significant risk in both directions. Chronic high-dose iodine (common in kelp supplements) causes both hypothyroidism (Wolff-Chaikoff effect) and hyperthyroidism (Jod-Basedow phenomenon), particularly in individuals with nodular thyroid disease or Hashimoto thyroiditis. The UL is 1,100 mcg/day. Kelp supplements often contain highly variable and sometimes dramatically excessive iodine concentrations.
Biological and Chemical Classification
- Scientific Name
- Potassium iodide / Sodium iodide / Molecular iodine
Mechanism of Action
Information not yet available for this ingredient profile.
Clinical Evidence of Effectiveness
Information not yet available for this ingredient profile.
Pharmacokinetics
Information not yet available for this ingredient profile.
Recommended Dosage
Information not yet available for this ingredient profile.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Mineral
- Evidence consistency: High consistency across studies (100%)
- Triggers both hypothyroidism and hyperthyroidism depending on thyroid status
- Kelp supplements have unpredictable and sometimes extremely high iodine content
- Particularly dangerous in Hashimoto thyroiditis and nodular goitre
- UL: 1,100 mcg/day — frequently exceeded by kelp and seaweed supplements
The available scientific evidence for Iodine (Potassium Iodide) indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 10/10 |
| Evidence transparency | 10/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 23 მარ 2026, 15:09
Evidence Distribution
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Observational / other LOW evidence YELLOWThree-dimensional imaging of the facial arteries: an overview of ocular vascular anatomy. ↗Jiang L et al.. Three-dimensional imaging of the facial arteries: an overview of ocular vascular anatomy.. Maxillofac Plast Reconstr Surg. 2025. PMID:41284111.PMID 41284111 ↗Journal Maxillofac Plast Reconstr SurgYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41284111/
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Observational / other LOW evidence YELLOWOptimization of In Vitro Germination, Viability Tests and Storage of Daylily (Hemerocallis spp.) Pollen. ↗Li W et al.. Optimization of In Vitro Germination, Viability Tests and Storage of Daylily (Hemerocallis spp.) Pollen.. Plants (Basel). 2025. PMID:40573842.PMID 40573842 ↗Journal Plants (Basel)Year 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40573842/
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Observational / other LOW evidence YELLOWMolecular Cloning and Heterologous Expression of the Mitochondrial ATP6 Gene from Kenaf (Hibiscus cannabinus) in Tobacco (Nicotiana tabacum). ↗Huang B et al.. Molecular Cloning and Heterologous Expression of the Mitochondrial ATP6 Gene from Kenaf (Hibiscus cannabinus) in Tobacco (Nicotiana tabacum).. Genes (Basel). 2025. PMID:40428301.PMID 40428301 ↗Journal Genes (Basel)Year 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40428301/
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Observational / other LOW evidence YELLOWEfficacy of Two Different Concentrations of Iodine-potassium Iodide Solution in Endodontic Retreatment: A Randomised Double-blinded Clinical Trial. ↗Sarkees M et al.. Efficacy of Two Different Concentrations of Iodine-potassium Iodide Solution in Endodontic Retreatment: A Randomised Double-blinded Clinical Trial.. Eur Endod J. 2025. PMID:40145486.PMID 40145486 ↗Journal Eur Endod JYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40145486/
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Observational / other LOW evidence YELLOWHigh-Resolution Iodine-Enhanced Micro-Computed Tomography of Intact Human Hearts for Detailed Coronary Microvasculature Analyses. ↗Reifart J et al.. High-Resolution Iodine-Enhanced Micro-Computed Tomography of Intact Human Hearts for Detailed Coronary Microvasculature Analyses.. J Imaging. 2024. PMID:39057744.PMID 39057744 ↗Journal J ImagingYear 2024Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/39057744/
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Observational / other LOW evidence YELLOWExcess Iodine Consumption Induces Oxidative Stress and Pancreatic Damage Independently of Chemical Form in Male Wistar Rats: Participation of PPAR-u03b3 and C/EBP-u03b2. ↗Arbez-Evangelista C et al.. Excess Iodine Consumption Induces Oxidative Stress and Pancreatic Damage Independently of Chemical Form in Male Wistar Rats: Participation of PPAR-u03b3 and C/EBP-u03b2.. Biology (Basel). 2024. PMID:39056661.PMID 39056661 ↗Journal Biology (Basel)Year 2024Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/39056661/
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Observational / other LOW evidence YELLOWUsing Low-cost Dyes to Visualize Glycogen Accumulation and Gut Integrity in Caenorhabditis elegans. ↗Jardim NS et al.. Using Low-cost Dyes to Visualize Glycogen Accumulation and Gut Integrity in Caenorhabditis elegans.. J Vis Exp. 2024. PMID:38465947.PMID 38465947 ↗Journal J Vis ExpYear 2024Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/38465947/
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Observational / other LOW evidence YELLOWAn In Vitro Study: Does Adding Iodine Potassium Iodide and Cetrimide to Calcium Hydroxide Paste Enhance Its Antimicrobial Effect Against Oral Biofilms? ↗Alamri HM et al.. An In Vitro Study: Does Adding Iodine Potassium Iodide and Cetrimide to Calcium Hydroxide Paste Enhance Its Antimicrobial Effect Against Oral Biofilms?. Cureus. 2023. PMID:38283497.PMID 38283497 ↗Journal CureusYear 2023Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/38283497/
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Observational / other LOW evidence YELLOWCase Series: Mixed Infectious Keratitis by Pythium insidiosum and Fungal Species. ↗Singh NK et al.. Case Series: Mixed Infectious Keratitis by Pythium insidiosum and Fungal Species.. Optom Vis Sci. 2023. PMID:38019963.PMID 38019963 ↗Journal Optom Vis SciYear 2023Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/38019963/
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Observational / other LOW evidence YELLOWPollen staining is a rapid and cost-effective alternative to marker-assisted selection for recessive waxy1 gene governing high amylopectin in maize. ↗Talukder ZA et al.. Pollen staining is a rapid and cost-effective alternative to marker-assisted selection for recessive waxy1 gene governing high amylopectin in maize.. Physiol Mol Biol Plants. 2022. PMID:36387980.PMID 36387980 ↗Journal Physiol Mol Biol PlantsYear 2022Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/36387980/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
One or more monitoring-level safety signals active
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for Iodine (Potassium Iodide). Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a moderate safety concern. Caution is advised, particularly at high doses or in sensitive populations.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Moderate classification for Iodine (Potassium Iodide)
A score of 4.5 places this ingredient in the Moderate band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
No active signals — S component is at neutral baseline (0.5), contributing no extra risk weight.
No major regulatory restrictions or advisories recorded across monitored jurisdictions (FDA, EMA, Health Canada, TGA, and others).
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.