Safety Profile
Known Safety Concerns
- Contributes to total caffeine load -- check combined caffeine intake
- Tannins inhibit iron absorption -- separate from iron supplements
- May increase blood pressure and heart rate
- Pregnancy: limit caffeine from all sources to <200 mg/day
Contraindications
- Contributes to total caffeine load -- check combined caffeine intake
- Tannins inhibit iron absorption -- separate from iron supplements
Interactions
Information not yet available for this ingredient profile.
Evidence and Scientific Findings
Ingredient Overview
Black tea extract contains caffeine, theaflavins, and tannins. Caffeine content varies by extract concentration — concentrated extracts can deliver significant caffeine doses. Tannins reduce iron absorption when taken with meals. Generally well tolerated but contributes to total caffeine load when combined with other caffeinated supplements.
Biological and Chemical Classification
- Scientific Name
- Camellia sinensis (black tea) leaf extract
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: Botanical
- Evidence consistency: High consistency across studies (100%)
- Contributes to total caffeine load -- check combined caffeine intake
- Tannins inhibit iron absorption -- separate from iron supplements
- May increase blood pressure and heart rate
- Pregnancy: limit caffeine from all sources to <200 mg/day
The available scientific evidence for Black Tea Extract 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: 25 მარ 2026, 12:45
Evidence Distribution
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Observational / other LOW evidence YELLOWBlack tea extract exerts a protective effect on diethylnitrosamine-induced hepatic precancerous lesions through the Nrf2 signaling pathway. ↗Wang X et al.. Black tea extract exerts a protective effect on diethylnitrosamine-induced hepatic precancerous lesions through the Nrf2 signaling pathway.. Tissue Cell. 2026. PMID:41435602.PMID 41435602 ↗Journal Tissue CellYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41435602/
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Observational / other LOW evidence YELLOWEffect of black tea extract on fresh rice noodles: multiple quality attributes and underlying mechanism. ↗Chen T et al.. Effect of black tea extract on fresh rice noodles: multiple quality attributes and underlying mechanism.. Food Chem X. 2025. PMID:41017919.PMID 41017919 ↗Journal Food Chem XYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41017919/
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Observational / other LOW evidence YELLOWTransfersome-Based Delivery of Optimized Black Tea Extract for the Prevention of UVB-Induced Skin Damage. ↗Benedetto N et al.. Transfersome-Based Delivery of Optimized Black Tea Extract for the Prevention of UVB-Induced Skin Damage.. Pharmaceutics. 2025. PMID:40870975.PMID 40870975 ↗Journal PharmaceuticsYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40870975/
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Observational / other LOW evidence YELLOWEco-friendly biosynthesis of copper oxide nanoparticles using black tea extract: multifaceted biological activities and potential as drug carriers. ↗Yalu00e7u0131n MS et al.. Eco-friendly biosynthesis of copper oxide nanoparticles using black tea extract: multifaceted biological activities and potential as drug carriers.. Int J Environ Health Res. 2025. PMID:40690538.PMID 40690538 ↗Journal Int J Environ Health ResYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40690538/
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Observational / other LOW evidence YELLOWInvestigation of optical band gap in PEO-based polymer composites doped with green-synthesized metal complexes using various models. ↗Mohammed HA et al.. Investigation of optical band gap in PEO-based polymer composites doped with green-synthesized metal complexes using various models.. RSC Adv. 2025. PMID:40626064.PMID 40626064 ↗Journal RSC AdvYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40626064/
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Observational / other LOW evidence YELLOWEvaluation of physio-mechanical and antimicrobial properties of indigenously developed food packaging films from corn starch/chitosan incorporated with Fe-NPs and black tea extract. ↗Asghar MA et al.. Evaluation of physio-mechanical and antimicrobial properties of indigenously developed food packaging films from corn starch/chitosan incorporated with Fe-NPs and black tea extract.. Int J Biol Macromol. 2025. PMID:40527372.PMID 40527372 ↗Journal Int J Biol MacromolYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40527372/
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Observational / other LOW evidence YELLOWRole of Black Tea in the Advancement of Nanotechnology: A Critical Review. ↗Sahu M et al.. Role of Black Tea in the Advancement of Nanotechnology: A Critical Review.. ACS Omega. 2025. PMID:40160723.PMID 40160723 ↗Journal ACS OmegaYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/40160723/
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Observational / other LOW evidence YELLOWPhotocatalytic removal of textile wastewater-originated methylene blue and malachite green dyes using spent black tea extract-coated silver nanoparticles. ↗Ali S et al.. Photocatalytic removal of textile wastewater-originated methylene blue and malachite green dyes using spent black tea extract-coated silver nanoparticles.. Sci Rep. 2025. PMID:39805978.PMID 39805978 ↗Journal Sci RepYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/39805978/
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Observational / other LOW evidence YELLOWEffect of green tea or black tea extract on lipid and protein oxidation in Cantonese sausage. ↗Xu W et al.. Effect of green tea or black tea extract on lipid and protein oxidation in Cantonese sausage.. J Sci Food Agric. 2025. PMID:39390704.PMID 39390704 ↗Journal J Sci Food AgricYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/39390704/
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Observational / other LOW evidence YELLOWBlack tea extracts enhance stress-induced sleep of Caenorhabditis elegans to resist UV damage. ↗Chen Y et al.. Black tea extracts enhance stress-induced sleep of Caenorhabditis elegans to resist UV damage.. Food Res Int. 2024. PMID:39614550.PMID 39614550 ↗Journal Food Res IntYear 2024Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/39614550/
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 Black Tea Extract. 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 Black Tea Extract
A score of 3.0 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.