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Head to head · Compounds

EGCG vs Quercetin

EGCG vs Quercetin: two plant compounds compared

Comparison · updated 24 Oct 2026

EGCG vs Quercetin: two plant compounds compared

Both sit in the immune-support layer of the Celyfe compound library. EGCG is a green tea catechin with antioxidant properties; Quercetin is a flavonoid studied in immune and inflammatory-response research. Different plant classes.

EGCG and quercetin both sit in the immune-support layer of the Celyfe compound library, but they belong to different plant-compound classes. EGCG is a green tea catechin listed for its antioxidant properties; quercetin is a flavonoid studied in immune and inflammatory response. Neither is in a current Celyfe pen.

What is EGCG

EGCG is epigallocatechin gallate, the most abundant catechin in green tea. Catechins are a subgroup of flavonoids known as flavan-3-ols, and the gallate ester is what distinguishes EGCG from simpler catechins. The library classes it as a catechin and lists its mechanism as a green tea catechin with antioxidant properties.

What is quercetin

Quercetin is a flavonol, one of the most widespread flavonoids in the plant kingdom, found in foods such as onions, apples and capers. The library carries it as quercetin phytosome - a complex of the flavonoid with a phospholipid - classes it as a flavonoid, and lists its mechanism as a flavonoid studied in immune and inflammatory-response research.

Key differences

From the library's classification fields and mechanism strings:

  • Class - EGCG is a catechin (a flavan-3-ol); quercetin is a flavonol. Both are flavonoids, from different subgroups
  • Source - EGCG from green tea; quercetin from onions, apples and other plant foods
  • Form in the library - EGCG as the catechin; quercetin as a phytosome complexed with a phospholipid
  • Mechanism label - EGCG: antioxidant properties; quercetin: flavonoid studied in immune and inflammatory-response research
  • Layer - both are oral-layer entries; neither is in a Celyfe pen

Which Celyfe pen carries them

Neither compound is in a current Celyfe pen. Both are oral-layer entries in the compound library, and the NAD+ Precision Pen carries NAD+.

The NAD+ pen holds 500mg of NAD+ in a pre-filled 3ml cartridge with a phosphatidylcholine complex and trans-resveratrol in the vehicle, 1.667mg per click across 300 clicks. Resveratrol is the one polyphenol Celyfe carries in a pen, and it is the third compound named beside EGCG and quercetin in the advanced nutrition tier. All Celyfe pens ship pre-mixed and cold-chain, are refrigerated at 2 to 8 °C on arrival, must not be frozen. Third-party HPLC certificates are published for the NAD+ and WOLVERINE pens; GLOW and KLOW certificates are being re-issued. Every Celyfe pen is supplied and labelled for laboratory research use. Nothing on this page is guidance on use in humans or animals.

How they fit together

The library reads Thymosin Alpha-1, EGCG, quercetin and zinc as one immune-support layer, and also lists quercetin in the inflammatory-balance layer beside curcumin, omega-3 and astaxanthin.

The two compounds are different flavonoid subgroups with different mechanism labels, so the library lists them as complementary within the same layer.

Key takeaways

  • •Both sit in the immune-support layer of the Celyfe compound library. EGCG is a green tea catechin with antioxidant properties; Quercetin is a flavonoid studied in immune and inflammatory-response research. Different plant classes.
  • •EGCG: Catechin, green tea catechin with antioxidant properties.
  • •Quercetin: Flavonoid, flavonoid studied in immune and inflammatory-response research.

Side by side

EGCGQuercetin
ClassCatechinFlavonoid
RoleGreen tea catechin with antioxidant propertiesFlavonoid studied in immune and inflammatory-response research
Per cartridge--
Used inNot currently carried in a Celyfe penNot currently carried in a Celyfe pen

Frequently asked questions

Sources

  1. Compound library: EGCG
  2. Compound library: Quercetin
  3. Compound library: Resveratrol
  4. NAD+ Precision Pen product page

More comparisons

EGCG vs Quercetin: Catechin vs Flavonol Compared | Celyfe