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Antioxidant

Camellia sinensis Extract (Green Tea Leaf)

Also known as: Green Tea Extract, EGCG, Epigallocatechin Gallate, Tea Polyphenols

B
Evidence

Camellia sinensis leaf extract is a polyphenol-rich botanical standardized for EGCG, the primary catechin compound associated with green tea's antioxidant and metabolic benefits. Substantial human evidence supports its use for cognitive support, metabolic health, and antioxidant protection.

Primary uses

  • Antioxidant support
  • Cognitive function and attention
  • Metabolic health and weight management
  • Cardiovascular health
  • Neuroprotection

How it works

  • EGCG-mediated antioxidant activity via free radical scavenging
  • Modulation of cellular signaling pathways (AMPK, MAPK)
  • Support for mitochondrial function
  • Potential enhancement of fat oxidation and thermogenesis

Dosage

Typical range
200–600 mg daily (EGCG content typically 90–270 mg at this dosage)
Timing
With meals or as part of daily routine; can be divided into 2–3 doses
With food
Can be taken with or without food; taking with meals may improve tolerability and absorption
Duration
Long-term daily use is safe; benefits typically observed over 4–8 weeks of consistent use
Special populations
Generally safe in pregnancy and lactation at typical dietary doses; pediatric and geriatric populations tolerate standard doses well

Forms

  • Powder extract· 70/100
  • Capsule· 70/100
  • Tablet· 70/100
  • Brewed tea· 70/100

Safety

Common side effects

  • Mild nausea or stomach upset (especially on empty stomach)
  • Jitteriness or sleep disruption in sensitive individuals (due to residual caffeine ~2–4% in extract)
  • Headache (rare)

Contraindications

  • Iron deficiency anemia (high polyphenol content may reduce iron absorption; separate dosing by 2+ hours)
  • Severe caffeine sensitivity (use decaffeinated forms if available)
  • Concurrent anticoagulation therapy (theoretical interaction; use cautiously and monitor)

Evidence notes

Well-established human trial data on green tea catechins; multiple RCTs demonstrate cognitive and metabolic effects. EGCG standardization (45%) is a recognized quality marker. Grade B rather than A due to modest effect sizes in some domains and heterogeneous study designs.

Grade B: Some human trials support key claims; further confirmation needed.

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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider.