Caffeine: effective % & pH 카페인
⏱ 1 min read
⚡ Quick answer: Caffeine: effective concentration 0.5–3% in eye formulas, optimal pH 4.5–7.0, evidence Moderate. Caffeine buys you a few hours of a smoother-looking under-eye. Judge it in the morning, not overnight — and do not expect it to touch pigment or hollowing.
How much Caffeine actually works? Here's the dosage, pH and evidence — the formulator-level read behind the % on a Korean label.
| Effective % | 0.5–3% in eye formulas |
|---|---|
| Optimal pH | 4.5–7.0 |
| Evidence | Moderate |
| Onset | minutes to hours (temporary) |
What the % on the label really means
Caffeine buys you a few hours of a smoother-looking under-eye. Judge it in the morning, not overnight — and do not expect it to touch pigment or hollowing.
⚠️ Ceiling: The effect is short-lived and reverses within hours. Whether more caffeine buys a longer or larger one has not really been tested — 5% eye serums exist, without evidence they outperform 1%.
Caffeine guide →How Caffeine works →
Sources: PubMed — Caffeine & skin ↗ · AAD skin-care basics ↗
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✍️ Written & reviewed by the KoreaPlus Editorial team — dermatologist-informed, cosmetic-science researched & source-cited. Last reviewed: 2026-08-23.
General educational information using cosmetic structure-function wording — not medical advice. Always patch-test new actives. © KoreaPlus.