Related Herbs
Botanicals connected by the same goals, effects, or research topics.
Herb Profile
Green Tea Extract
Camellia sinensis
Green Tea Extract (Camellia sinensis) carries a Grade B rating — moderate evidence.
Last reviewed: •4 sources citedReport a correctionProfile-wide ·B Moderate
Use extra caution — Safety evidence: limited human safety evidence and rare case reports. Details
- Evidence
- Moderate Evidence
- Typical onset
- Varies by prep
- Safety rating
- Moderate caution
- Best for
- Metabolic
- Avoid / review if
- Liver Disease, Stimulants
At a glance
From this profile's structured data- Evidence
- Grade B
- Safety
- Safety evidence: limited human safety evidence and rare case reports.
- Profile context
- metabolic
Safety
Safety & Cautions
Safety evidence: limited human safety evidence and rare case reports. Concentrated, catechin rich green tea extracts can cause liver injury, with risk influenced by dose and fasting exposure; this does not apply automatically to brewed tea or food use.
Elevated caution
Caution level: Elevated. One caution category applies — read it before use.
- Liver-SensitiveLiver-related caution language appears in the profile.
Detailed safety fields
Pregnancy, breastfeeding, and contraindications
- Liver Disease
- Stimulants
Safety classifications
- Liver-Sensitive: Liver-related caution language appears in the profile.
Full safety note
- Safety evidence: limited human safety evidence and rare case reports. Concentrated, catechin rich green tea extracts can cause liver injury, with risk influenced by dose and fasting exposure; this does not apply automatically to brewed tea or food use.
Safety labels
- Liver-Sensitive
Evidence
Evidence Summary
Evidence lens
Useful signal, but study design, dose, and population still matter.
ModerateModerate Evidence
Human clinical evidence: Present in source signals
Mechanistic / preclinical: Mechanism mapped — Metabolic Regulation · Vascular Function Support
Research maturity: Established research — Long Term Human Evidence May Be Limited.
Safety boundary: Safety note available — Safety evidence: limited human safety evidence and rare case reports.
This profile cites 4 human studies.
Study design details
Evidence Grade
Grade B: Moderate Evidence
Evaluation of methodological rigor, population reach, and evidence alignment.
- Design Match
- Randomized controlled trial
- Risk of Bias
- Low
- Consistency
- Not assessed
Strongest recorded design is a randomized controlled trial, drawn from 4 recorded studies, 2 in people.
How evidence grades work
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
- Strong
- Multiple RCTs, consistent direction, adequate effect size
- Moderate
- Some RCTs or consistent observational data in humans
- Preliminary / Mixed
- Animal or in-vitro only, or conflicting human data
- Traditional / Theoretical
- Traditional use only; no controlled human trials
Clinical Study Summaries (4)1 human evidence source · 1 human trial · ~115 participants across 1 human evidence source with reported N · Consistency not yet classifiable
Filter by study class
Showing 4 of 4 studies.
What the evidence actually shows
This table contains 4 structured sources, including 1 human evidence source; 1 is a human trial. Across 1 human evidence source with a reported sample size, the approximate participant total is 115; overlapping publications may include some of the same people.
| Study | Design | N | Dose | Duration | Population | Outcome | Result & magnitude | Source |
|---|---|---|---|---|---|---|---|---|
Chen IJ et al. · Clin Nutr · 2016 Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | n=115 | — | — | — | — | — | PubMed → |
Common Herbal Dietary Supplement-Drug Interactions Asher GN et al. · Am Fam Physician · 2017 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
PubMed indexed authors · 2012 Background | Narrative review Summarizes selected literature without the full prespecified search and selection methods of a systematic review. | — | — | — | — | — | — | PubMed → |
PubMed · J Biol Chem · 2005 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | PubMed → |
Dosing & Timing
- Dose guidance
- 300 800 mg EGCG/day
How Green Tea Extract works
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Green Tea Extract Works
CompoundTarget / ReceptorMechanismEffect / Outcome
Mechanisms & biological pathways (preclinical)
- Metabolic Regulation
- Vascular Function Support
Compare related active botanicals
Explore botanicals with similar chemistry, effects, or safety considerations in the Botanical Activity Atlas.
Guides that use Green Tea Extract
Goal guides
Condition guides
Compare & Sourcing
Compare side-by-side tradeoffs or verify active marker guidelines.
Sourcing options
Green Tea Extract product picks
Recommendation status
Product recommendations are not shown for this profile because the current site safety and monetization policy does not permit them.
Product form & quality guidelines
When sourcing Green Tea Extract, verify the label for:
- Standardized extract: Confirm active content percentages on the supplement facts panel (e.g. standardized to specific marker compounds) rather than simple raw herb weights.
- Third-party testing: Look for independent purity labels (USP, NSF, ConsumerLab, or Eurofins) to ensure the product is free from heavy metals, solvents, and contaminants.
- Form bioavailability: Ensure the form matches evidence-supported configurations (e.g. standardized active extracts like bacosides, withanolides, or curcuminoids) for optimal onset and digestion tolerance.
Continue comparing
Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Editorial Review
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
Help improve this profile
Was this useful for your research?
These controls record only the page and the structured choice you make when analytics consent is enabled. Please don’t include personal medical information in research requests.
Was this evidence summary clear?
Did you find what you were researching?
Free safety checklist
Get the Green Tea Extract research notes
Evidence summaries, dosing context, and safety updates for this herb — straight to your inbox.
We use your email to send the checklist and occasional evidence-first supplement updates. Unsubscribe anytime. Privacy policy.