Ingredient Guide

EGCG

EGCG (epigallocatechin gallate) is the primary antioxidant polyphenol found in green tea, used topically for antioxidant and mild anti-inflammatory support.

Evidence reviewedAugust 8, 2026
Medical reviewDr. Abdurrahman Efem
Practical reviewMerve Akkaya
Best-supported context: antioxidant supportAny time of dayCan be unstable in formulas
Dark protective EGCG serum bottle beside the large title “EGCG” on a warm ivory background.

Evidence profile

How confident is this recommendation?

Confidence is shown in plain categories, not a numerical trust score.

Recommendation confidenceModerate

Reasonable mechanism-level and some clinical support, tempered by formulation stability challenges.

Best-supported concentrationNo strongly standardized cosmetic percentage; often paired with green tea extract broadly

Formula stability matters as much as concentration.

Better-supported usesAntioxidant support, mild anti-inflammatory benefit

This is where the most consistent supporting evidence exists.

More limited usesAs a standalone or primary anti-ageing treatment

Best understood as a supportive antioxidant addition.

Biggest uncertaintyReal-world stability and delivery in typical consumer formulas

EGCG degrades relatively quickly when exposed to light, heat and air, which can limit its practical effectiveness in poorly formulated or packaged products.

What it is

Green tea’s primary antioxidant, with real formulation challenges.

EGCG is the most abundant and most studied polyphenol in green tea, credited with much of green tea’s antioxidant reputation in both ingested and topical research.

Its main practical limitation in skincare is stability: EGCG oxidizes relatively quickly when exposed to light, heat and air, so opaque, airtight packaging and proper formulation matter significantly for real-world performance.

Evidence at a glance

Useful evidence, with important limits.

Moderate evidence

Antioxidant support

EGCG has reasonable evidence for antioxidant activity that may help defend skin against oxidative stress.

Limit: Real-world effectiveness depends heavily on formula stability and freshness.

Limited evidence

Anti-inflammatory and soothing benefit

Some research suggests mild anti-inflammatory properties.

Limit: Effect sizes are modest, and this is not a primary treatment for inflammatory skin conditions.

Concentration guide

Stability matters more than a specific percentage.

Concentration or form How to interpret it Practical use
Formulated in opaque, airtight packagingHelps preserve EGCG’s antioxidant activity over the product’s shelf life.Prioritise packaging and freshness over percentage claims.

Skin Candid view: A lower concentration in a well-preserved, properly packaged formula is likely more useful than a higher concentration that has already begun to oxidize.

How to use it

Use consistently, and store products away from light and heat.

1Apply to clean skinCan be used morning or evening depending on the product.
2Store products properlyKeep away from direct sunlight and heat to preserve stability.
3Use fresher products soonerAntioxidant serums, including EGCG-based ones, are best used within their recommended timeframe after opening.

Freshness matters: An older or improperly stored EGCG product may have lost much of its antioxidant activity even before you notice a visible change.

Using it with other ingredients

Reduce routine complexity before testing combinations.

Vitamin C

A common antioxidant pairing for combined defence.

Read the Vitamin C guide

Niacinamide

Both are generally gentle and layer well together.

Read the Niacinamide guide

Side effects and caution

Generally well tolerated.

  • Irritation is uncommon at typical cosmetic concentrations.
  • Those with caffeine sensitivity should note that green tea extracts may contain trace caffeine, though this is generally not a topical concern.
  • Discontinue if unexpected irritation develops.

Frequently asked questions

EGCG, without the pressure to tolerate everything.

Is EGCG the same as green tea extract?

EGCG is the primary active antioxidant polyphenol within green tea extract, which contains other compounds as well.

Why does my green tea serum turn brown?

This is a sign of oxidation, meaning the antioxidant activity has likely degraded; proper storage helps slow this process.

Can EGCG replace vitamin C?

They work through related but distinct antioxidant mechanisms and are often used together rather than as substitutes for each other.

Sources reviewed

Primary evidence and medical guidance behind this page

  1. NIH NCBI Bookshelf (StatPearls): Moisturizers
  2. American Academy of Dermatology: How to select a sunscreen

Sources support the general editorial conclusions shown here. They do not prove that every product containing this ingredient will produce the same result.