Identity
Green tea, as a cosmetic ingredient, is extract of Camellia sinensis — the same plant behind green, black, and oolong tea. What matters on skin isn't the leaf but a family of molecules inside it: catechins, a type of polyphenol. The headline catechin is EGCG (epigallocatechin-3-gallate), the most abundant and most active, alongside EGC, ECG, and EC plus traces of caffeine and L-theanine.
This entry is deliberately the whole-leaf extract — the material an INCI list calls Camellia Sinensis Leaf Extract. Isolated EGCG is a different, purified substance with its own identifiers; the extract contains it but the two are not the same ingredient, and must not be matched as one.
Development & history
- Green tea is one of the most-studied botanicals in skincare — which makes it a good test of which claims decades of research actually support.
- Its evidence is strongest where the marketing is quietest (oil control, calming, antioxidant defence) and weakest where the marketing is loudest (anti-ageing wrinkle reduction).
- Two formulation facts shape every green tea product: EGCG degrades in light and air, and it penetrates skin poorly — so packaging and formulation matter more than the number on the label.
Mechanism (as proposed)
Green tea's catechins act through antioxidant chemistry: they neutralise free radicals from UV and pollution, and in lab and short-exposure human work topical EGCG applied before UV lowered oxidative-stress markers in skin. That is a genuine, measurable supporting effect — an antioxidant layer that works under sunscreen, never as a substitute for it.
In the reference literature EGCG also appears to act on several pathways behind oily, congested skin at once — oil production, the local inflammatory response, and microbial balance — which is why the human evidence for the look of oily, blemish-prone skin is its strongest suit. Those are the mechanisms behind the "reduces sebum" and "anti-inflammatory" framings, and they stay in the reference: this cosmetic entry keeps the claim at the level of appearance — clearer-, more balanced-, calmer-looking skin — never "reduces sebum", "anti-inflammatory", "prevents skin cancer" or "replaces sunscreen". Two honest cautions round it out: EGCG is unstable in light (a large share can decompose within an hour of strong light exposure) and penetrates skin poorly, staying mostly in the outermost layer — so a green tea product is only as good as its formulation and its opaque, air-restricting packaging. Judge the bottle, not the percentage.