Safety Profile
Known Safety Concerns
- Very low bioavailability (~9%) -- therapeutic value questionable
- Copper depletion with chronic supplementation
- FDA advisory against zinc nasal sprays -- permanent anosmia risk
- Nausea at high doses
Contraindications
- Very low bioavailability (~9%) -- therapeutic value questionable
- Copper depletion with chronic supplementation
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
Zinc oxide has very low bioavailability (approximately 9%) compared to organic zinc forms. It is the cheapest form found in many low-cost multivitamins. Despite poor absorption, accumulated high doses can deplete copper. The intranasal zinc oxide products linked to permanent anosmia have prompted FDA advisory against zinc nasal products.
Biological and Chemical Classification
- Scientific Name
- Zinc oxide (ZnO)
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%)
- Very low bioavailability (~9%) -- therapeutic value questionable
- Copper depletion with chronic supplementation
- FDA advisory against zinc nasal sprays -- permanent anosmia risk
- Nausea at high doses
The available scientific evidence for Zinc Oxide 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: 24 მარ 2026, 11:01
Evidence Distribution
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Observational / other LOW evidence YELLOWMOF-Derived ZnO Thin Films with Uniformly Dispersed Pt Nanoparticles for High-Performance Acetone Detection. ↗Alharbi H et al.. MOF-Derived ZnO Thin Films with Uniformly Dispersed Pt Nanoparticles for High-Performance Acetone Detection.. ACS Omega. 2026. PMID:41867553.PMID 41867553 ↗Journal ACS OmegaYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41867553/
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Observational / other LOW evidence YELLOWAssessment of the efficacy of agarose and agarose augmented with zinc oxide, carbon dots, and graphitic carbon nitride nanostructures in the restoration… ↗ElDeeb HM et al.. Assessment of the efficacy of agarose and agarose augmented with zinc oxide, carbon dots, and graphitic carbon nitride nanostructures in the restoration of historic tintype.. RSC Adv. 2026. PMID:41858934.PMID 41858934 ↗Journal RSC AdvYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41858934/
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Observational / other LOW evidence YELLOWExposure to Zinc Oxide and Selenium Nanoparticles in Japanese Quail: Oxidative Stress, Inflammatory Responses, and Histopathological Outcomes. ↗Noreen T et al.. Exposure to Zinc Oxide and Selenium Nanoparticles in Japanese Quail: Oxidative Stress, Inflammatory Responses, and Histopathological Outcomes.. J Appl Toxicol. 2026. PMID:41858267.PMID 41858267 ↗Journal J Appl ToxicolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41858267/
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Observational / other LOW evidence YELLOWOne-Step Pulsed Electrodeposition of ZnO/ZnP Composite Coatings on Titanium Implants for Enhanced Antibacterial Activity and Biocompatibility. ↗Chen J et al.. One-Step Pulsed Electrodeposition of ZnO/ZnP Composite Coatings on Titanium Implants for Enhanced Antibacterial Activity and Biocompatibility.. ACS Appl Bio Mater. 2026. PMID:41854528.PMID 41854528 ↗Journal ACS Appl Bio MaterYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41854528/
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Observational / other LOW evidence YELLOWDevelopment of antibacterial PLA-based melt-blown nonwovens via incorporation of P(3HB-co-4HB) and ZnO nanoparticles: Processing and property evaluation. ↗Yu J et al.. Development of antibacterial PLA-based melt-blown nonwovens via incorporation of P(3HB-co-4HB) and ZnO nanoparticles: Processing and property evaluation.. Int J Biol Macromol. 2026. PMID:41850454.PMID 41850454 ↗Journal Int J Biol MacromolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41850454/
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Observational / other LOW evidence YELLOW3D-printed doped optical waveguides for sensing applications: graphite- and zinc-doped structures. ↗Soto-Bernal JJ et al.. 3D-printed doped optical waveguides for sensing applications: graphite- and zinc-doped structures.. Appl Opt. 2026. PMID:41842142.PMID 41842142 ↗Journal Appl OptYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41842142/
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Observational / other LOW evidence YELLOWImpact of low-crude protein and insoluble fiber diets on post-weaning diarrhea, growth performance, intestinal morphology, and gene expression for nursery pigs with… ↗Hagen C et al.. Impact of low-crude protein and insoluble fiber diets on post-weaning diarrhea, growth performance, intestinal morphology, and gene expression for nursery pigs with natural rotavirus and subject to enterotoxigenic Escherichia coli F18+ experimental infection.. Transl Anim Sci. 2026. PMID:41841044.PMID 41841044 ↗Journal Transl Anim SciYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41841044/
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Observational / other LOW evidence YELLOWApplication of small molecule inhibitors to probe the mechanism underlying nanomaterial pulmonary inflammatory responses in vitro. ↗Lofty M et al.. Application of small molecule inhibitors to probe the mechanism underlying nanomaterial pulmonary inflammatory responses in vitro.. Nanotoxicology. 2026. PMID:41841012.PMID 41841012 ↗Journal NanotoxicologyYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41841012/
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Observational / other LOW evidence YELLOWHierarchically Restructured Antibacterial Electrodes for Neural Interfaces: Electrochemical and Microstructural Evolution under Extended Cycling. ↗Panchal K et al.. Hierarchically Restructured Antibacterial Electrodes for Neural Interfaces: Electrochemical and Microstructural Evolution under Extended Cycling.. ACS Appl Mater Interfaces. 2026. PMID:41834187.PMID 41834187 ↗Journal ACS Appl Mater InterfacesYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41834187/
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Observational / other LOW evidence YELLOWEnhanced lasing emission from the improved hybrid structure of silver nanowires and zincu00a0oxide. ↗Altamimi TA et al.. Enhanced lasing emission from the improved hybrid structure of silver nanowires and zincu00a0oxide.. Appl Opt. 2025. PMID:41842206.PMID 41842206 ↗Journal Appl OptYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41842206/
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 Zinc Oxide. 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 low safety concern under normal conditions of use.
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 Low classification for Zinc Oxide
A score of 3.5 places this ingredient in the Low 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.